tag:blogger.com,1999:blog-21966290612846746412024-03-04T20:35:07.424-08:00STRATEGIC INTERVENTION MATERIALSOUND
Submitted by:
Patrika G. Entendez
Rhudyn B. Celeste
Japheth Gregory T. Alag
IV-Boyle
Submitted to:
Mrs. Jennifer JovitaUnknownnoreply@blogger.comBlogger5125tag:blogger.com,1999:blog-2196629061284674641.post-83965599829947931042011-02-20T05:00:00.001-08:002011-02-27T04:40:40.395-08:00ENRICHMENT CARD<div style="color: red;"><span style="font-size: large;"><br />
</span></div><div style="color: red;"><span style="font-size: large;">A. State how important Sound is.</span></div><div style="color: red;"><span style="font-size: large;">B. How do sounds differ?</span></div><div style="color: red;"><span style="font-size: large;">C. How does your ear receive sound?</span></div><span style="color: red; font-size: large;">D. </span><span style="font-size: large;"><span style="color: red;">How is sound transmitted and received via a telephone?</span></span><div style="color: red;"><span style="font-size: large;"><br />
</span></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2196629061284674641.post-41855834572912975472011-02-20T04:59:00.001-08:002011-02-27T04:57:45.607-08:00ASSESMENT CARD<div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><b><span style="font-size: small;">Direction: Choose the letter of the correct answer.</span></b></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><br />
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</div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;">1. <b> </b>It i s a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><br />
a. Sound</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"> b. Music</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"> c. Melody</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><br />
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</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;">2. <span>Sound is restricted to the frequency range of 20 Hz to 20 000 Hz to which human ear is sensitive. waves with frequencies below this audible range called _______________. </span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span><br />
</span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span> a. Sound</span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span> b. Infrasound</span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span> c. Ultrasound</span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span><br />
</span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span>3. </span><span><span style="background-color: white;">Those above or greater than 20 000 Hz are referred to as __________________.</span></span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><br />
</div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span><span style="background-color: white;"> </span></span></span><span style="font-size: small;"><span>a. Sound</span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span> b. Infrasound</span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span> c. Ultrasound</span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><br />
</div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;">4. In studying and detecting sounds within the body, doctors use the <b>_________________.</b></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><br />
</div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"> a. Microscope</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"> b. Stethoscope</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"> c. Telescope</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><b><br />
</b></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;">5. The highness or lowness of sound is called ___________________.</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><br />
</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"> a. Pitch</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"> b. Noise</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"> C. Sound</span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span style="line-height: 115%;"> </span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span><span style="background-color: white;"> </span></span></span></div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><br />
</div><div style="color: magenta; font-family: Arial,Helvetica,sans-serif;"><span style="font-size: small;"><span><span style="background-color: white;"> </span></span><span><span style="background-color: white;"></span></span><span><span style="background-color: white;"></span></span></span></div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2196629061284674641.post-43668225149826257052011-02-20T04:41:00.000-08:002011-02-27T05:11:13.124-08:00ACTIVITY CARD<div style="color: magenta;"> <b style="font-family: "Courier New",Courier,monospace;">Direction: Fill in the blanks.</b></div><div style="color: magenta; font-family: "Courier New",Courier,monospace;"><br />
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</div><div style="color: blue; font-family: Verdana,sans-serif;"><span style="font-size: small;">1. _______ ______ are produced by vibrating objects.</span></div><div style="color: blue; font-family: Verdana,sans-serif;"><br />
</div><div style="color: blue; font-family: Verdana,sans-serif;"><span style="font-size: small;">2. Sound waves are _____________________ waves.</span></div><div style="color: blue; font-family: Verdana,sans-serif;"><br />
</div><div style="color: blue; font-family: Verdana,sans-serif;"><span style="font-size: small;">3. Loudness depends on the ________________ of vibration.</span></div><div style="color: blue; font-family: Verdana,sans-serif;"><br />
</div><div style="color: blue; font-family: Verdana,sans-serif;"><span style="font-size: small;">4. Pitch depends on ____________________ of vibration.</span></div><div style="color: blue; font-family: Verdana,sans-serif;"><br />
</div><div style="color: blue; font-family: Verdana,sans-serif;"><span style="font-size: small;">5. Sound waves travels ____________ in solids and _____________ in gases. </span></div><div style="color: magenta;"></div><div style="color: magenta;"></div><div style="color: magenta;"></div><div style="color: magenta;"></div><div style="color: magenta;"></div><div style="color: magenta;"><br />
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</div>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-2196629061284674641.post-43615903222856238552011-02-20T04:40:00.000-08:002011-02-28T03:26:02.007-08:00REFERENCE CARD<div style="color: magenta; font-family: Times,"Times New Roman",serif;"><i><span style="font-size: large;"><b>Science and Technology </b></span></i></div><div style="color: magenta; font-family: Times,"Times New Roman",serif;"><i><span style="font-size: large;"><b>Physics IV Textbook</b></span></i><br />
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<i><span style="font-size: large;"><b>www.wikipedia.org </b></span></i></div>Unknownnoreply@blogger.com1tag:blogger.com,1999:blog-2196629061284674641.post-89803617491006399182011-02-20T04:25:00.000-08:002011-02-28T04:01:04.056-08:00GUIDE CARD<div style="color: black; font-family: "Courier New",Courier,monospace; text-align: left;"><div class="separator" style="clear: both; text-align: center;"><span style="font-size: x-large;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgr37npVEriItZIlQSOWUGnsQnNpbUTjryyonlJU_N8OzGQe4ZRke2BkJmqC9SazpkEiDQQ8wxarR2gN-MfubHzvQm6vAPZggNP9AblYTwPULi2SD5Z1qzlLqzDL7VCudmOREJ4yjUbpNk/s1600/p6.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><b>communication</b></a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="color: magenta;">-is the transmission and reception of meaningful information. people communicate through their senses. Normally, they communicate with each other within range of sight and hearing by visual and vocal means, that is , by light and sound</span>.</div><div class="separator" style="clear: both; text-align: center;"><br />
</div><div class="separator" style="clear: both; color: magenta; text-align: center;">Through various technological devices such as the telephone, telegraph, radio, television, radar, radio telescope orbiting satellites, microwave relays, and lasers as well as the advances made in the field of electronics, human communication is the beneficiary of immeasurable favor. Until now, barriers of time and distance prevented efficient and speedy interaction. </div><span style="font-size: x-large;"><b><u>Nature of Sound</u></b></span></div><div style="color: black; font-family: "Courier New",Courier,monospace; text-align: left;"><br />
</div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhXy0r5fHlwoBC7aglkkLDhnuTtpc35trt7_t6I_NffXG1m7MCYIYLBiw8kcJIktzxg9jZkt0BvduS4UNorIZ3BOeillq1O5MVgUqLID8P5JS0jfmH5dnNmY5EWL2UwcEEn0GwWmAptQc/s1600/BMA_Sound.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="260" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjhXy0r5fHlwoBC7aglkkLDhnuTtpc35trt7_t6I_NffXG1m7MCYIYLBiw8kcJIktzxg9jZkt0BvduS4UNorIZ3BOeillq1O5MVgUqLID8P5JS0jfmH5dnNmY5EWL2UwcEEn0GwWmAptQc/s400/BMA_Sound.jpg" width="400" /></a></div><div style="color: black; font-family: "Courier New",Courier,monospace; text-align: left;"><span style="font-size: x-large;"><b><br />
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<span style="color: magenta; font-size: x-large;"><b>Sound</b></span><span style="color: black;"> </span><u style="color: blue;"><span style="font-family: Arial,Helvetica,sans-serif;">is a </span><span style="font-family: Arial,Helvetica,sans-serif;">mechanical wave</span><span style="font-family: Arial,Helvetica,sans-serif;"> that is an </span><span style="font-family: Arial,Helvetica,sans-serif;">oscillation</span><span style="font-family: Arial,Helvetica,sans-serif;"> of </span><span style="font-family: Arial,Helvetica,sans-serif;">pressure</span><span style="font-family: Arial,Helvetica,sans-serif;"> transmitted through a </span><span style="font-family: Arial,Helvetica,sans-serif;">solid</span><span style="font-family: Arial,Helvetica,sans-serif;">, </span><span style="font-family: Arial,Helvetica,sans-serif;">liquid</span><span style="font-family: Arial,Helvetica,sans-serif;">, or </span><span style="font-family: Arial,Helvetica,sans-serif;">gas</span><span style="font-family: Arial,Helvetica,sans-serif;">, composed of </span><span style="font-family: Arial,Helvetica,sans-serif;">frequencies</span><span style="font-family: Arial,Helvetica,sans-serif;"> within the range of hearing and of a </span><span style="font-family: Arial,Helvetica,sans-serif;">level sufficiently strong</span><span style="font-family: Arial,Helvetica,sans-serif;"> to be heard, or the sensation stimulated in organs of hearing by such vibrations.</span></u><br />
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<u><sup class="reference" id="cite_ref-0" style="font-family: Arial,Helvetica,sans-serif;"><span style="color: black;"></span></sup></u><br />
<div style="text-align: center;"><sup class="reference" id="cite_ref-0" style="font-family: Arial,Helvetica,sans-serif;"><span style="color: black;"><span style="font-size: large;"><span style="color: red;">Sound is what we hear:</span><br />
<span style="color: #4c1130;">VIBRATIONS shake the AIR</span><br />
<span style="color: #f1c232;">AIR shakes the EARDRUM</span><br />
<span style="color: blue;">NERVES sense the SHAKE</span><br />
<span style="color: #b45f06;">BRAIN feels the SOUND</span></span></span></sup></div><div style="text-align: left;"><sup class="reference" id="cite_ref-0" style="font-family: Arial,Helvetica,sans-serif;"><span style="color: black;"><span style="font-size: large;"><span style="color: #b45f06;"></span></span></span></sup><sup class="reference" id="cite_ref-0" style="font-family: Arial,Helvetica,sans-serif;"><span style="color: black;"><span style="font-size: large;"><span style="color: #b45f06;"> <span style="color: black;"> </span></span></span></span></sup></div><div style="text-align: left;"><sup class="reference" id="cite_ref-0" style="font-family: Arial,Helvetica,sans-serif;"><span style="color: black;"><span style="font-size: large;"><span style="color: #b45f06;"><span style="color: black;">Different sounds:</span></span></span></span></sup></div><div style="text-align: left;"><sup class="reference" id="cite_ref-0" style="font-family: Arial,Helvetica,sans-serif;"><span style="color: black;"><span style="font-size: large;"><span style="color: #b45f06;"> <span style="color: purple;"> LOUD/SOFT</span><br />
<span style="color: #a64d79;">HIGH/LOW pitch</span><br />
<span style="color: red;">SHORT/LONG</span></span></span></span></sup><br />
<div style="color: red;"><span style="font-size: large;"><b><br />
</b></span></div><div style="color: magenta;"><span style="font-size: large;"><b> </b><span style="font-family: Verdana,sans-serif; font-size: small;"> Electronic vocal communication devices such as the telephone require the mutual conversion of sound and electricity.</span></span></div><div style="color: magenta; font-family: Verdana,sans-serif;"><span style="font-size: small;"> We live in a world of sound. Anywhere we go and whatever we do, we hear sounds. Some of these <br />
are familiar to us, a friend's voice, the chirping of birds, the ticking of the clock, the barking of the dogs, the beating of your heat. Certain sounds like music are pleasant to the ears; others are not. We call the latter noise. Different sounds have different effects. For instance, music soothes and relaxes. The crashing sounds of explosives can make us feel nervous.</span></div><div style="color: magenta; font-family: Verdana,sans-serif;"><br />
</div><div style="color: magenta; font-family: Verdana,sans-serif;"><span style="font-size: small;"> Sound is restricted to the frequency range of 20 Hz to 20 000 Hz to which human ear is sensitive. waves with frequencies below this audible range are called <b style="background-color: white; color: red;"><u>infrasounds</u> </b><span style="background-color: white; color: red;"><span style="color: magenta;">and those above or greater than 20 000 Hz are reffered to as</span> <b><u>ultrasounds</u>.</b></span></span></div><div style="color: magenta; font-family: Verdana,sans-serif;"><br />
</div><div style="color: magenta; font-family: Verdana,sans-serif;"><span style="font-size: small;"><span style="background-color: white;"> Sound waves are longitudinal waves. they are produced by a series of vibrations parallel to the direction of travel of the waves. When you pluck the strings of a guitar, the strings look hazy as they vibrate. Touch your throat while talking and you will feel the vibrations of your vocal cords. When you ring a bell, you pull the string and move it back and forth to produce sound. In each of these examples, the source of sound is a vibrating object.</span></span><br />
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</span></span></div><div style="color: magenta; font-family: Verdana,sans-serif;"><u><b>Propagation of sound waves</b></u><br />
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How do sound waves spread or propagate from the source toward the space around it? What kind of medium is needed for their propagation?<br />
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Like water waves, sound waves need a medium to spread in.Sound is a sequence of waves of pressure which propagates through compressible media such as air or water. They can even travel through narrow openings and around corners, but not in an empty space or vacuum.<br />
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<div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">The behavior of sound propagation is generally affected by three things:</span></div><ul type="disc"><li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">A relationship between density and pressure. This relationship, affected by temperature, determines the speed of sound within the medium.</span></li>
</ul><ul type="disc"><li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">The propagation is also affected by the motion of the medium itself. For example, sound moving through wind. Independent of the motion of sound through the medium, if the medium is moving, the sound is further transported.</span></li>
</ul><ul type="disc"><li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">The viscosity of the medium also affects the motion of sound waves. It determines the rate at which sound is attenuated. For many media, such as air or water, attenuation due to viscosity is negligible.</span></li>
</ul><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">When sound is moving through a medium that does not have constant physical properties, it may be refracted (either dispersed or focused).</span></div><div class="MsoNormal"><br />
</div><div class="MsoNormal"><span style="font-size: 12pt; line-height: 115%;">Considering a vibrating tuning fork. As the prongs of the fork move back and forth, they disturb air molecules close to them creating a back and forth movement of the air parallel to the direction of the waves. These air molecules likewise transfer their motion to the neighboring particles and to the other molecules. The air molecules then strike your eardrum, making it vibrate. Nearly all sounds reach you with air as the transmitting medium. Dense gases are better transmitters of the sounds than rare gases, as you climb a mountain, you must speak a little louder to be heard. Air on mountains is less dense than in the lowlands. It does not transmit sound so readily.</span></div><div class="MsoNormal"><br />
</div><div class="MsoNormal" style="line-height: normal;"><b><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Perception of sound</span></b></div><div class="MsoNormal"><span style="font-size: 12pt; line-height: 115%;">For humans, hearing is normally limited to frequencies between about 20 <a href="http://en.wikipedia.org/wiki/Hertz" title="Hertz">Hz</a> and 20,000 Hz (20 <a href="http://en.wikipedia.org/wiki/KHz" title="KHz">kHz</a>), although these limits are not definite. The upper limit generally decreases with age. Other <a href="http://en.wikipedia.org/wiki/Species">species</a> have a different range of hearing. For example, dogs can perceive vibrations higher than 20 kHz. As a signal perceived by one of the major <a href="http://en.wikipedia.org/wiki/Sense" title="Sense">senses</a>, sound is used by many species for <a href="http://en.wikipedia.org/wiki/Defence_mechanism_%28biology%29" title="Defence mechanism (biology)">detecting danger</a>, <a href="http://en.wikipedia.org/wiki/Navigation">navigation</a>, <a href="http://en.wikipedia.org/wiki/Predation">predation</a>, and <a href="http://en.wikipedia.org/wiki/Communication">communication</a>. <a href="http://en.wikipedia.org/wiki/Earth">Earth</a>'s <a href="http://en.wikipedia.org/wiki/Atmosphere">atmosphere</a>, <a href="http://en.wikipedia.org/wiki/Hydrosphere" title="Hydrosphere">water</a>, and virtually any <a href="http://en.wikipedia.org/wiki/Physical_phenomenon" title="Physical phenomenon">physical phenomenon</a>, such as <a href="http://en.wikipedia.org/wiki/Fire">fire</a>, <a href="http://en.wikipedia.org/wiki/Rain">rain</a>, <a href="http://en.wikipedia.org/wiki/Wind">wind</a>, <a href="http://en.wikipedia.org/wiki/Ocean_surface_wave" title="Ocean surface wave">surf</a>, or <a href="http://en.wikipedia.org/wiki/Earthquake">earthquake</a>, produces (and is characterized by) its unique sounds. Many species, such as <a href="http://en.wikipedia.org/wiki/Frog" title="Frog">frogs</a>, <a href="http://en.wikipedia.org/wiki/Bird" title="Bird">birds</a>, <a href="http://en.wikipedia.org/wiki/Marine_mammals" title="Marine mammals">marine</a> and terrestrial <a href="http://en.wikipedia.org/wiki/Mammal" title="Mammal">mammals</a>, have also developed special <a href="http://en.wikipedia.org/wiki/Organ_%28anatomy%29" title="Organ (anatomy)">organs</a> to produce sound. In some species, these produce <a href="http://en.wikipedia.org/wiki/Bird_vocalization" title="Bird vocalization">song</a> and <a href="http://en.wikipedia.org/wiki/Speech_communication" title="Speech communication">speech</a>. Furthermore, <a href="http://en.wikipedia.org/wiki/Human" title="Human">humans</a> have developed culture and technology (such as <a href="http://en.wikipedia.org/wiki/Music">music</a>, <a href="http://en.wikipedia.org/wiki/Telephone">telephone</a> and <a href="http://en.wikipedia.org/wiki/Radio">radio</a>) that allows them to generate, record, transmit, and broadcast sound.</span></div><div class="MsoNormal"><br />
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</div><h3><span class="mw-headline"><span style="color: black; font-size: 12pt; line-height: 115%;">Sound wave properties and characteristics</span></span><span style="color: black; font-size: 12pt; line-height: 115%;"></span></h3><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Sound <a href="http://en.wikipedia.org/wiki/Wave" title="Wave">waves</a> are often simplified to a description in terms of <a href="http://en.wikipedia.org/wiki/Sinusoid" title="Sinusoid">sinusoidal</a> <a href="http://en.wikipedia.org/wiki/Plane_wave" title="Plane wave">plane waves</a>, which are characterized by these generic properties:</span></div><ul type="disc"><li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"><a href="http://en.wikipedia.org/wiki/Frequency">Frequency</a>, or its inverse, the period</span></li>
<li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"><a href="http://en.wikipedia.org/wiki/Wavelength">Wavelength</a></span></li>
<li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"><a href="http://en.wikipedia.org/wiki/Wavenumber">Wave number</a></span></li>
<li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"><a href="http://en.wikipedia.org/wiki/Amplitude">Amplitude</a></span></li>
<li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"><a href="http://en.wikipedia.org/wiki/Intensity_%28physics%29" title="Intensity (physics)">Intensity</a></span></li>
<li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"><a href="http://en.wikipedia.org/wiki/Speed_of_sound" title="Speed of sound">Speed</a></span></li>
<li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"><a href="http://en.wikipedia.org/wiki/Direction_%28geometry,_geography%29" title="Direction (geometry, geography)">Direction</a></span></li>
</ul><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Sometimes speed and directions are combined as a <a href="http://en.wikipedia.org/wiki/Velocity">velocity</a> <a href="http://en.wikipedia.org/wiki/Vector_%28geometric%29" title="Vector (geometric)">vector</a>; wave number and direction are combined as a <a href="http://en.wikipedia.org/wiki/Wave_vector">wave vector</a>.</span></div><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"><a href="http://en.wikipedia.org/wiki/Transverse_wave" title="Transverse wave">Transverse waves</a>, also known as <a href="http://en.wikipedia.org/wiki/Shear_stress" title="Shear stress">shear</a> waves, have the additional property, <i><a href="http://en.wikipedia.org/wiki/Polarization_%28waves%29" title="Polarization (waves)">polarization</a></i>, and are not a characteristic of sound waves.</span></div><div class="MsoNormal" style="line-height: normal;"><br />
</div><h3><span class="mw-headline"><span style="color: black; font-size: 12pt; line-height: 115%;">Speed of sound</span></span></h3><div class="MsoNormal"><span style="font-size: 12pt; line-height: 115%;">The speed of sound depends on the medium the waves pass through, and is a fundamental property of the material. In general, the speed of sound is proportional to the <a href="http://en.wikipedia.org/wiki/Square_root">square root</a> of the <a href="http://en.wikipedia.org/wiki/Ratio">ratio</a> of the <a href="http://en.wikipedia.org/wiki/Elastic_modulus">elastic modulus</a> (stiffness) of the medium to its <a href="http://en.wikipedia.org/wiki/Density">density</a>. Those physical properties and the speed of sound change with ambient conditions. For example, the speed of sound in gases depends on <a href="http://en.wikipedia.org/wiki/Temperature">temperature</a>. In 20 <a href="http://en.wikipedia.org/wiki/Celsius" title="Celsius">°C</a> (68 <a href="http://en.wikipedia.org/wiki/Fahrenheit" title="Fahrenheit">°F</a>) air at the <a href="http://en.wikipedia.org/wiki/Sea_level">sea level</a>, the speed of sound is approximately 343 <a href="http://en.wikipedia.org/wiki/Metre_per_second" title="Metre per second">m/s</a> (1,230 <a href="http://en.wikipedia.org/wiki/Kilometres_per_hour" title="Kilometres per hour">km/h</a>; 767 <a href="http://en.wikipedia.org/wiki/Miles_per_hour" title="Miles per hour">mph</a>) using the formula "v = (331 + 0.6T) m/s". In fresh water, also at 20 °C, the speed of sound is approximately 1,482 m/s (5,335 km/h; 3,315 mph). In <a href="http://en.wikipedia.org/wiki/Steel">steel</a>, the speed of sound is about 5,960 m/s (21,460 km/h; 13,330 mph). The speed of sound is also slightly sensitive (a second-order <a href="http://en.wikipedia.org/wiki/Anharmonicity" title="Anharmonicity">an harmonic</a> effect) to the sound amplitude, which means that there are nonlinear propagation effects, such as the production of harmonics and mixed tones not present in the original sound (see <a href="http://en.wikipedia.org/wiki/Parametric_array">parametric array</a>).</span></div><h3><span class="mw-headline"><span style="color: black; font-size: 12pt; line-height: 115%;">Acoustics</span></span></h3><div class="MsoNormal"><span style="font-size: 12pt; line-height: 115%;">Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics technology may be called an acoustical or audio engineer. The application of acoustics can be seen in almost all aspects of modern society with the most obvious being the audio and noise control industries.</span></div><div class="MsoNormal"><br />
</div><h3><span class="mw-headline"><span style="color: black; font-size: 12pt; line-height: 115%;">Noise</span></span></h3><div class="MsoNormal"><span style="font-size: 12pt; line-height: 115%;">Noise is a term often used to refer to an unwanted sound. In science and engineering, noise is an undesirable component that obscures a wanted signal.</span></div><div class="MsoNormal"><br />
</div><h2><span class="mw-headline"><span style="font-size: 12pt;">Sound pressure level</span></span><span style="font-size: 12pt;"></span></h2><span style="font-family: "Times New Roman","serif"; font-size: 12pt; line-height: 115%;">Sound pressure is the difference, in a given medium, between average local pressure and the pressure in the sound wave. A square of this difference (i.e., a square of the deviation from the equilibrium pressure) is usually averaged over time and/or space, and a square root of this average provides a <a href="http://en.wikipedia.org/wiki/Root_mean_square">root mean square</a> (RMS) value. For example, 1 <a href="http://en.wikipedia.org/wiki/Pascal_%28unit%29" title="Pascal (unit)">Pa</a> RMS sound pressure (94 dBSPL) in atmospheric air implies that the actual pressure in the sound wave oscillates between (1 atm <img alt="-\sqrt{2}" border="0" class="tex" height="32" src="file:///C:/DOCUME%7E1/user/LOCALS%7E1/Temp/msohtmlclip1/01/clip_image001.gif" width="32" />Pa) and (1 atm </span> <m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac><br />
<div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">that is between 101323.6 and 101326.4 Pa. Such a tiny (relative to atmospheric) variation in air pressure at an <a href="http://en.wikipedia.org/wiki/Audio_frequency"><span style="color: blue;">audio frequency</span></a> is perceived as a <a href="http://en.wikipedia.org/wiki/Deaf" title="Deaf"><span style="color: blue;">deafening</span></a> sound, and can cause hearing damage, according to the table below.</span></div><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">As the human ear can detect sounds with a wide range of amplitudes, sound pressure is often measured as a level on a logarithmic <a href="http://en.wikipedia.org/wiki/Decibel"><span style="color: blue;">decibel</span></a> scale. The <b>sound pressure level</b> (SPL) or <i>L</i><sub>p</sub> is defined as</span></div><br />
<m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac><br />
<div class="MsoNormal" style="line-height: normal; margin: 0in 0in 0.0001pt 0.5in;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">where <i>p</i> is the <a href="http://en.wikipedia.org/wiki/Root-mean-square" title="Root-mean-square"><span style="color: blue;">root-mean-square</span></a> sound pressure and <i>p</i><sub>ref</sub> is a reference sound pressure. Commonly used reference sound pressures, defined in the standard <a href="http://en.wikipedia.org/wiki/American_National_Standards_Institute" title="American National Standards Institute"><span style="color: blue;">ANSI</span></a> S1.1-1994, are 20 <a href="http://en.wikipedia.org/wiki/Micropascal" title="Micropascal"><span style="color: blue;">µPa</span></a> in air and 1 <a href="http://en.wikipedia.org/wiki/Micropascal" title="Micropascal"><span style="color: blue;">µPa</span></a> in water. Without a specified reference sound pressure, a value expressed in decibels cannot represent a sound pressure level.</span></div><br />
<m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac><br />
<div class="MsoNormal" style="line-height: normal; margin: 0in 0in 0.0001pt 0.5in;"><m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Since the human <a href="http://en.wikipedia.org/wiki/Ear"><span style="color: blue;">ear</span></a> does not have a flat <a href="http://en.wikipedia.org/wiki/Responsivity" title="Responsivity"><span style="color: blue;">spectral response</span></a>, sound pressures are often <a href="http://en.wikipedia.org/wiki/Frequency"><span style="color: blue;">frequency</span></a> weighted so that the measured level matches perceived levels more closely. The <a href="http://en.wikipedia.org/wiki/International_Electrotechnical_Commission"><span style="color: blue;">International Electrotechnical Commission</span></a> (IEC) has defined several weighting schemes. <a href="http://en.wikipedia.org/wiki/A-weighting"><span style="color: blue;">A-weighting</span></a> attempts to match the response of the human ear to noise and A-weighted sound pressure levels are labeled dBA. C-weighting is used to measure peak levels.</span></div><div class="MsoNormal"><br />
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</div><div style="color: magenta; font-family: Verdana,sans-serif;"><m:smallfrac m:val="off"><m:dispdef><m:lmargin m:val="0"><m:rmargin m:val="0"><m:defjc m:val="centerGroup"><m:smallfrac m:val="off"><m:dispdef><m:lmargin m:val="0"><m:rmargin m:val="0"><m:defjc m:val="centerGroup"><br />
</m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div><div style="color: red; font-family: Verdana,sans-serif;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgr37npVEriItZIlQSOWUGnsQnNpbUTjryyonlJU_N8OzGQe4ZRke2BkJmqC9SazpkEiDQQ8wxarR2gN-MfubHzvQm6vAPZggNP9AblYTwPULi2SD5Z1qzlLqzDL7VCudmOREJ4yjUbpNk/s1600/p6.JPG" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="53" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgr37npVEriItZIlQSOWUGnsQnNpbUTjryyonlJU_N8OzGQe4ZRke2BkJmqC9SazpkEiDQQ8wxarR2gN-MfubHzvQm6vAPZggNP9AblYTwPULi2SD5Z1qzlLqzDL7VCudmOREJ4yjUbpNk/s320/p6.JPG" width="320" /></a></div><br />
</div><div style="color: red;"></div><div style="color: purple;"><br />
</div><div style="color: purple;"><m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div><div class="MsoNormal" style="color: magenta; line-height: normal; margin: 0in 0in 0.0001pt 0.5in;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">where <i>p</i> is the </span><a href="http://en.wikipedia.org/wiki/Root-mean-square" title="Root-mean-square"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">root-mean-square</span></a><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"> sound pressure and <i>p</i><sub>ref</sub> is a reference sound pressure. Commonly used reference sound pressures, defined in the standard </span><a href="http://en.wikipedia.org/wiki/American_National_Standards_Institute" title="American National Standards Institute"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">ANSI</span></a><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"> S1.1-1994, are 20 </span><a href="http://en.wikipedia.org/wiki/Micropascal" title="Micropascal"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">µPa</span></a><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"> in air and 1 </span><a href="http://en.wikipedia.org/wiki/Micropascal" title="Micropascal"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">µPa</span></a><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"> in water. Without a specified reference sound pressure, a value expressed in decibels cannot represent a sound pressure level.</span></div><div class="MsoNormal" style="color: magenta; line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Since the human </span><a href="http://en.wikipedia.org/wiki/Ear"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">ear</span></a><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"> does not have a flat </span><a href="http://en.wikipedia.org/wiki/Responsivity" title="Responsivity"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">spectral response</span></a><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">, sound pressures are often </span><a href="http://en.wikipedia.org/wiki/Frequency"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">frequency</span></a><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"> weighted so that the measured level matches perceived levels more closely. The </span><a href="http://en.wikipedia.org/wiki/International_Electrotechnical_Commission"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">International Electrotechnical Commission</span></a><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"> (IEC) has defined several weighting schemes. </span><a href="http://en.wikipedia.org/wiki/A-weighting"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">A-weighting</span></a><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"> attempts to match the response of the human ear to noise and A-weighted sound pressure levels are labeled dBA. C-weighting is used to measure peak levels.</span></div><div class="MsoNormal" style="color: magenta; line-height: normal;"><br />
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</div><div class="MsoNormal" style="color: magenta; line-height: normal;"><m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div><m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac><br />
<div class="MsoNormal"><b><span style="font-size: 16pt; line-height: 115%;">Characteristics of Sound waves.</span></b></div><div class="MsoNormal"><br />
</div><div class="MsoNormal"><b><span style="font-size: 16pt; line-height: 115%;"> <span style="color: magenta;"> </span></span></b><span style="color: magenta; font-size: 12pt; line-height: 115%;">How do sounds differ? The crack of thunder may be very loud; a whisper may be soft and low. A cicada sound is shrill; a dog’s growl is like a deep bass. Some voices have pleasing quality, while others are harsh or grating. These examples indicate that sounds differ. Each is distinct from the others. Sounds may be regarded as “fingerprints” of the persons or objects producing them. They differ from one another in 3 ways, namely; (a) loudness or intensity (b) pitch (c) quality.</span></div><div class="MsoNormal"><br />
</div><div class="MsoNormal"><b><span style="font-size: 12pt; line-height: 115%;">LOUDNESS AND INTENSITY</span></b></div><div class="MsoNormal"><br />
</div><div class="MsoNormal"><span style="font-size: 12pt; line-height: 115%;"> <span style="color: magenta;"> </span><span style="color: magenta;">If a small pebble were thrown with force into the water, the waves to be produced would have greater amplitude than if the pebble were dropped into the water gently. The amplitude is the maximum displacement from a wave’s equilibrium position.</span></span></div><div class="MsoNormal" style="color: magenta;"><br />
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</div><div class="MsoNormal" style="color: magenta;"><span style="font-size: 12pt; line-height: 115%;"><b style="color: black;">Energy</b><b> </b>is always carried by sound waves. A vibrating body, like the guitar string or the drumhead, produces loud songs when much energy is transferred to it. Sound waves transfer energy through the particles of the medium. In studying and detecting sounds within the body, doctors use the <b>stethoscope,</b> which has a rubber tubing attached to an end piece that is placed on the area to be examined. The tubing transmits the sounds from the patient’s diaphragm to the doctor’s ears.</span></div><div class="MsoNormal"><span style="color: magenta; font-size: 12pt; line-height: 115%;">Sound is a form of mechanical vibration which propagates through any mechanical medium. It is closely related to the ability of the human ear to perceive sound. The wide outer area of the ear is maximized to collect sound vibrations. It is amplified and passed through the outer ear, striking the eardrum, which transmits sounds into the inner ear. Auditory nerves fire according to the particular vibrations of the sound waves in the inner ear, which designate such things as the pitch and volume of the sound. The ear is set up in an optimal way to interpret sound energy in the form of vibrations.</span><span style="color: black; font-size: 13pt; line-height: 115%;"></span></div><div class="MsoNormal"><br />
</div><div class="MsoNormal" style="line-height: normal;"><b><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Pitch</span></b></div><div class="MsoNormal" style="color: magenta;"><br />
</div><div class="MsoNormal" style="color: magenta;"><span style="font-size: 12pt; line-height: 115%;"> Sounds are low, others are high. The highness or lowness of sounds is called pitch, a characteristics determined by our senses. The frequency of sound waves determines the pitch of a sound, the higher the frequency of a sound wave, the higher the pitch.</span></div><div style="color: magenta;"><span style="font-family: "Calibri","sans-serif";">Pitch</span><span style="font-family: "Calibri","sans-serif";"> represents the perceived <a href="http://en.wikipedia.org/wiki/Fundamental_frequency">fundamental frequency</a> of a sound. It is one of the major <a href="http://en.wikipedia.org/wiki/Auditory_system" title="Auditory system">auditory</a> attributes of <a href="http://en.wikipedia.org/wiki/Musical_tone" title="Musical tone">musical tones</a> along with <a href="http://en.wikipedia.org/wiki/Duration_%28music%29" title="Duration (music)">duration</a>, <a href="http://en.wikipedia.org/wiki/Loudness">loudness</a>, <a href="http://en.wikipedia.org/wiki/Timbre">timbre</a>, and <a href="http://en.wikipedia.org/wiki/Sound_localization" title="Sound localization">sound source location</a>.</span></div><div style="color: magenta;"><span style="font-family: "Calibri","sans-serif";">Pitches are compared as "higher" and "lower" in the sense that allows the construction of melodies. Pitch may be quantified as a <a href="http://en.wikipedia.org/wiki/Frequency">frequency</a> in cycles per second (<a href="http://en.wikipedia.org/wiki/Hertz">hertz</a>), however pitch is not a purely objective physical property, but a subjective <a href="http://en.wikipedia.org/wiki/Psychoacoustics" title="Psychoacoustics">psychoacoustical</a> attribute of <a href="http://en.wikipedia.org/wiki/Sound">sound</a>.</span></div><div style="color: magenta;"><span style="font-family: "Calibri","sans-serif";">Pitch is a subjective sensation in which a listener can assign <a href="http://en.wikipedia.org/wiki/Musical_tone" title="Musical tone">tones</a> to relative positions on a musical scale based primarily on the frequency of vibration. Pitches are sometimes quantified as <a href="http://en.wikipedia.org/wiki/Frequency" title="Frequency">frequencies</a> (cycles per second, or <a href="http://en.wikipedia.org/wiki/Hertz">hertz</a>), by comparison with <a href="http://en.wikipedia.org/wiki/Sine_wave" title="Sine wave">sine waves</a>. Pitches in Hz usually match very nearly the repetition rate of sound waves other than sine waves, too</span><br />
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<m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac><br />
<div class="MsoNormal" style="color: black;"><b><span style="font-size: 20pt; line-height: 115%;">The beginning of electronic communications</span></b></div><div class="MsoNormal" style="color: black;"><br />
</div><div class="MsoNormal" style="color: black;"><m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div><div style="text-indent: 0.5in;">Electronic communications is any communication based on electricity. The basis for this wasn’t properly harnessed until both direct current and alternating current electricity were mastered and popularized in the late 19<sup>th</sup> century. Thomas Edison warned that direct current electricity was safer, and thus should form the basis of a national power company. Unfortunately, alternating current electricity had better transmission capabilities and although it is more dangerous, became the basis for modern electrical power. These basic truths would ultimately form the foundation for modern electronic communication. All communications formed with alternating electrical current will be investigated.</div>What we know of as electronic communications originated with the telegraph. The telegraph was a simple electrical circuit that transmitted electrical impulses across country via wire. It had two signals, a dot and a dash. This formed a code that could be interpreted as words. This code was Morse code. Over time, the code would be translated into all languages and became state-of-the-art technology.<br />
The next major communications invention was the telephone. The “plain old telephone” has changed very little since it was invented in the early 19<sup>th</sup> century. It has just become more popular and accepted since its invention. It was patented by Alexander Gram Bell in 1876 but more than likely invented by Innocenzo Manzetti and was originally called the “speaking telegraph”. The history indicates that the telephone as actually being demonstrated in England some nine years before Alexander Bell filed his patent in America. The idea that the phone was invented in America is a misconception. Regardless of its origins, there was nothing as convenient as the phone until wireless radio transmissions became fashionable quite a while later.<br />
The idea of sending messages via radio waves didn’t become popular until Faraday proved that such transmissions were possible and done easily and cheaply. Wireless transmissions evolved from simple messages with ranges of only a few miles to the cellular phones we use today. Wireless transmissions eventually have become the premier communications medium. Wired transmissions are looked at as backwards and troublesome in comparison. This viewpoint comes from the fact that wires are prone to trouble. Cables break, get dug up and become disconnected from equipment. Virtually every wired industry in the world today wishes to become wireless. There are many business benefits to dropping the cable. The most important of which is to increase reliability. Today customers see wires as a weakness and low standard of technology. Modern communications, with the way cell phones work, have grown by leaps in bounds in terms of size, scale and the ability to reach others. Now a person with just a satellite phone can call someone on the other side of the planet without an operator and complex operation. This was unthinkable just 50 years ago.<br />
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</div><div style="color: black;"><m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div><div class="MsoNormal" style="color: black; line-height: normal;"><b><span style="font-family: "Times New Roman","serif"; font-size: 13.5pt;">A brief history of electronic communication</span></b></div><div class="MsoNormal" style="color: black; line-height: normal;"><m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Communication is as old as humankind - and indeed as old as our evolutionary ancestors. </span></div><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Until the dawn of electronic communication, rapid communication was limited to the distance we could shout or see. </span></div><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Communication at a distance was limited to the speed of a person, a horse or a boat (or a chain of beacons or visual semaphores). </span></div><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Electronic communication has enabled us to communicate: </span></div><ul type="disc"><li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">over much greater distances - even as far as space probes to the planets </span></li>
<li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">quickly - electronic communication occurs at or close to the speed of light </span></li>
<li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">large amounts of information </span></li>
<li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">cheaply </span></li>
<li class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">with large numbers of people - most people in industrial countries have access to TV, radio, telephones etc. </span></li>
</ul><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">This radical change in communication technology has been associated with profound changes in our lives - socially, for business and industry, our knowledge of the world and the ability of others to educate, persuade, inform, entertain and mislead us. </span></div><div class="MsoNormal" style="color: black; line-height: normal;"><br />
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<div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">Because electronic communications systems often involve millions of separate ‘Sending’ and ‘Listening’ subsystems e.g. telephones, radios or TV sets they cannot be redesigned quickly. So, for example, the Morse telegraph led to the conventional telephone, which in turn led to the mobile telephone. The modern mobile telephone includes features that date back to the telegraph of more than 160 years ago. In fact it was only in 2000 that Morse Code ceased to be taught in wireless telegraphy courses.</span></div><div class="MsoNormal" style="line-height: normal;"><br />
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</div><div class="MsoNormal" style="color: black; line-height: normal;"><m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div><div class="MsoNormal" style="color: black; line-height: normal;"><b><span style="font-family: "Times New Roman","serif"; font-size: 18pt;">The telephone system</span></b></div><div class="MsoNormal" style="color: black; line-height: normal;"><br />
</div><div class="MsoNormal" style="color: black; line-height: normal;"><m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div><h2>The system</h2>The University of St Andrews telephone system employs an Ericsson MD110 (running BC12.2 software) with 17 Line Interface Modules (LIMs), distributed in 5 exchanges throughout the University. These LIMs connect approximately 6700 digital and analogue extension ports to the system. (8000 extensions max.). The 5 exchanges are linked by a University owned, dedicated optical fibre Broadband Premises Network (BPN) utilising Fibre Distributed Digital Interface (FDDI) protocol at 100Mbs. Each exchange is connected to the BPN via Ericsson multiplexor units.<br />
With effect from 01 February 2003 the University has provided telephone services for the student population living in University owned Halls of Residence (ResTel). Of the 6700 total extensions in use in the University approximately 3600 are in student residences. Ericsson's DNA software is used by the Telephone Office to administer moves and changes on a daily basis, including defining classes of service and category set-ups. <br />
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</div><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;"> </span> <m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div><h2 style="color: black;">Voice mail</h2><h2 style="color: black;"><m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></h2>The University uses Call Express for its voice mail system to provide voice mail services for staff and Students on a single platform.<br />
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<h2 style="color: black;">Call logging</h2>The Telecoms and Infrastructure Manager is actively involved in developing a number of interlinked programs, utilising the data generated by the MD110, in Microsoft Visual Basic 6 in order to analyse the running telephone system and to ensure its effective use by staff and students.<br />
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<div class="MsoNormal" style="color: black; line-height: normal;"><b><span style="font-family: "Times New Roman","serif"; font-size: 18pt;">Rapid long-distance communication relies on the telegraphed until 1877.</span></b></div><br />
<h2 style="color: black;"> <m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></h2><div class="MsoNormal" style="line-height: normal; text-indent: 0.5in;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">The foundation of electronic communication begins with the introduction of the electromagnet. The British inventor William Sturgeon (1783-1850) displayed the power of the electromagnet. He uses seven-ounce piece of iron, wrapped with wires which was sent with a current from a single cell battery, and was able to lift nine pounds of object.</span></div><div class="MsoNormal" style="line-height: normal;"><span style="font-family: "Times New Roman","serif"; font-size: 12pt;">An American named Joseph Henry (1797-1878) was able to demonstrate Sturgeons device for long distance communication. It was done by sending an electronic current over a mile of wire to activate an electromagnet, this activity causes a bell to strike. This was the beginning of the use of the telegraph.</span></div></div><div style="color: magenta;"><br />
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<div class="MsoNormal" style="color: black;"><b><span style="font-size: 20pt; line-height: 115%;"> </span></b> <m:smallfrac m:val="off"> <m:dispdef> <m:lmargin m:val="0"> <m:rmargin m:val="0"> <m:defjc m:val="centerGroup"> <m:wrapindent m:val="1440"> <m:intlim m:val="subSup"> <m:narylim m:val="undOvr"> </m:narylim></m:intlim> </m:wrapindent> </m:defjc></m:rmargin></m:lmargin></m:dispdef></m:smallfrac></div> The telegraph is a device which uses electricity to send messages. The telegraph was developed by Samuel F.B Morse. He is a professor at the New York University. Samuel Morse used a telegraphed key to encode messages. This was done by using a special code called the Morse Code. This code was consisted of dot and dashes representing the letters of the alphabet and made by making and breaking the transmitter circuit. The pulses of the current deflected an electromagnet, which moved a marker to produce written codes on a strip of paper. The following year, the device was modified to emboss the paper with dots and dashes.<br />
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Later, the operation developed into sending by key and receiving by ear. The electric signals are sent through wires to the receiver end where the received signals are converted to sound by a sounder. A trained Morse operator could transmit 40 to 50 words per minute.<br />
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Until 1877, all rapid long distance communications depended upon the telegraph. That year, a rival technology developed that would again change the face of communication --------- the telephone.<br />
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<div style="color: black;"><b><span style="font-size: x-large;">The Telephone System</span></b></div><div style="color: magenta;"><span style="font-size: x-large;"> <span style="font-size: small;">Alexander Graham Bell's success with the telephone came as a direct result of his attempts to improve the telegraph.</span></span></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNvT6oo3uYwBvooS6iwgNT4-ALlYEIS0xTsDYCItBJfFOp5oGYEsPeonMNYcVtc4c6ameiJybQHSBcWA6P5UDATAPqqbXq_YtGPpsIWpq9rcqvRUkHMvoiHwofwsfHqkHmQ9cdAp-kaBE/s1600/220px-Alexander_Graham_Bell.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNvT6oo3uYwBvooS6iwgNT4-ALlYEIS0xTsDYCItBJfFOp5oGYEsPeonMNYcVtc4c6ameiJybQHSBcWA6P5UDATAPqqbXq_YtGPpsIWpq9rcqvRUkHMvoiHwofwsfHqkHmQ9cdAp-kaBE/s1600/220px-Alexander_Graham_Bell.jpg" /></a></div><div style="color: magenta;"><span style="font-size: x-large;"><span style="font-size: small;"> </span></span></div><div style="color: magenta;"><span style="font-size: x-large;"><span style="font-size: small;"> </span></span></div><div style="color: magenta;"><br />
</div><div style="color: magenta;"><span style="font-size: x-large;"><span style="font-size: small;"> Born on March 3, 1847, in Edinburgh, Scotland, Alexander Graham Bell was the son and grandson of authorities in elocution and the correction of speech. Educated to pursue a career in the same specialty, his knowledge of the nature of sound led him not only to teach the deaf, but also to invent the telephone.</span></span></div><div style="color: magenta;"><br />
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</div><div style="color: black;"><span style="font-size: x-large;"><b>The Telephone</b></span></div><div style="color: black;"><span style="font-size: x-large;"><b> </b><span style="color: magenta; font-size: small;">Bell's extensive knowledge of the nature of sound and his understanding of music enabled him to conjecture the possibility of transmitting multiple messages over the same wire at the same time. Although the idea of a multiple telegraph had been in existence for some time, Bell offered his own musical or harmonic approach as a possible practical solution. His "harmonic telegraph" was based on the principle that several notes or signals differed in pitch. They had proven that different tones would vary the strength of an electric current in a wire. To achieve success they therefore needed only to build a working transmitter with a membrane capable of varying electronic current and a receiver that would reproduce these variations in audible frequencies.</span></span></div><div style="color: black;"><span style="font-size: x-large;"><span style="font-size: small;"></span></span><b><span style="font-size: x-large;"><span style="font-size: small;"><br />
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