Sound
SOUND WAVES
FREQUENCY
The frequency of the wave is the number of crests or troughs that pass by over a certain amount of time. If ten waves were made per second, then the frequency would be 10 per second.
AMPLITUDE
The distance between the resting point and a crest or trough. You can think of amplitude as the height of the wave.
Types of waves
HOW SOUNDS ARE MADE
Sound is produced when matter vibrates. A vibrating object transfers energy all around it. The sound waves cause air particles to bunch together then spread apart. This pattern continues as the sound waves spread out in all directions. The air particles do not move across the room, they only vibrate back and forth. |
OSCILLOSCOPE
How you hear sound
Humans detect sound waves with their ears. The sound waves are picked up by the outer ear and sent to the inner ear. In the inner ear, the sound waves are changed into signals that travel to the brain. The brain interprets the signals as sounds.
All sounds require matter through which to travel. That matter is called the MEDIUM of the sound. A MEDIUM can be a solid, a liquid, or a gas. Sound CANNOT travel through empty space.
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Sounds typically travel faster through solids and slower through gases. Sound also travels faster at warmer temperatures than at colder temperatures.
PITCH
The PITCH of a sound is how high or low it is. Pitch depends on the frequency of the sound wave. The higher the frequency, the higher the pitch of the sound.
VOLUME
Another property of sound is VOLUME. Volume is how loud or soft a sound is. Volume changes with the energy of a sound wave, the more energy the wave carries and the louder the sound.