Sound Notes

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How We Hear

All sounds come from vibrations.

1. An object exp. Cymbals makes a sound by vibrating.

2. The vibrations pass through air by making air particles vibrate.

3. These vibrations make your ear drum vibrate.

4. Then it gets converted into a electrical signal and via the auditory nerve it gets sent to the brain.

Different Pitches

A sound is made by an object or material vibrating. For example to make a sound with a guitar a string has to vibrate. We can raise the pitch of the guitar by doing these three things.

1. Increasing the length

2. Tightening the string

3. The sizes of the strings

Seeing Sound

An oscilloscope allows us to study (or see) the pitch and volume of the sound.

A High Pitch Sound

A Low Pitch Sound

A Quiet Sound

A Loud Sound

Traveling Sound

Sound travels the fastest through a solid since the particles are close together. The second fastest is through a liquid followed by a gas. Light can travel through Carbon Dioxide at 260 m/s, Oxygen 340 m/s, Water 1480 m/s and Glass 4540 m/s. Speed= Distance/time = 100/0.34 = 294 m/s

Sound does not travel through a vacuum (space).

The Dangers Of Sound

The higher the decibel the more damage it causes to your ear permanent or temporary. If your talking at a normal volume it is 50 dB a motor cycle is 110 dB, above 140 it causes permanent damage to your ear these sounds include an explosion and a thunderclap.