sound+wave+--instruments+++-nanaka

All sounds are produced by vibrating object, and they travel as compressional waves. Here is a simple applet to see the movement of compressional wave. You can change frequency and amplitude here to see how the wave differ. []

Each instruments sounds different, which is mainly caused by the difference of intensity, pitch, and tone. All kinds of instruments combine them in their own way, and produce nice music.


 * INTENSITY,** known as loudness or amplitude, cause the sound difference. The more energy they have, the higher its amplitude. It's measured in the unit called decibel.

__Fundamental__: the lowest pitch __Overtones__: the one that has higher frequencies than fundamental __Harmonics__: those, vibrating in whole number multiples of the fundamentals __Second harmonics__: the one whose frequency is two times the fundamental, and sound one octave higher, Because all the different overtones of a sound gives a unique pattern, that everybody in the world has different pattern of overtones. It can be used for detectives just like the fingerprints. Voice identification equipment is also used as advanced security system to recognize the person.
 * TONE** cause the difference in how we hear it. When an instrument vibrates to produce the sound, it vibrates with many frequencies at the same time, and each of those frequencies produces a wave. So, the tone, or sound quality depends on the combination of those different frequencies of the sound waves.

__**Length** shorter=higher__ Shorter the string is, higher the frequency, so it has higher pitch. → musician press finger on the string = shorten its length. More fingers he / she adds = shorter she makes Larger the diameter is, thicker it is, so,slower it vibrates, and have lower frequencies. → A 10mm diameter, thin string will have a frequency twice as high as the one with a 20 mm diameter. → Thin string sound one octave above thicker one Tighter the string is, higher the frequency. →When string players tighten or loosen their strings, they are altering the pitches to make them in tune Denser molecules vibrate at slower speeds, so more dense the string is, the slower it will vibrate, and the lower its frequency will be. →Instrument's strings are made of different materials; string used for low pitches will be made of denser material than the string used for high pitch.
 * FREQUENCY,** or pitch, is affected by length, diameter, tension, and density.
 * __Diameter__** __lar__g__er=lower__
 * __Tension__** __tighter = higher__
 * __Density__** __denser= lower__

[] In this website, you can have a little fun playing piano. You can click around the keyboard, then it will show you the frequency, amplitude, and period of each key. You can see the actual wave! not only numbers!

The author of this applet is Mr.Paul Flavin. I don't have much information about the author or reason right now; I'm currently asking him about it. http://www.frontiernet.net/~imaging/ (home page)