1. Properties of Sound
Chapter 16 Section 2

2. Amplitude
Amplitude of a sound wave indicates the amount of energy in the wave
Longitudinal wave’s amplitude is the tightness of compression (pressure)
Also measured by separation of rarefaction
Intensity of sound is amount of energy that moves through an area
If intensity is great, energy is great, and wave travels farther
Loudness is human perception of intensity

3. Loudness
Humans perceive loudness changes when intensity is multiplied by 10
10 times more intensity is perceived as twice as loud
Scale to measure loudness is the decibel scale
Faintest sound average person can hear is 0 dB
Sounds with loudness above 120 dB can harm hearing
YouTube - Science of Sound

4. Pitch Pitch is human perception of frequency Remember, frequency is:
Number of waves that pass in one second
Measured in Hertz (Hz)
Average human can hear from 20 Hz to Hz
Frequencies greater than Hz are called ultrasonic
Frequencies less than 20 Hz are called infrasonic
Frequency and Pitch

5. Sound Important qualities: Pitch Resonance Overtones
YouTube - Wine glass resonance in slow motion YouTube - The Physics of Woodwinds: a Recorder's Resonances
Overtones
Tuning instruments
YouTube - Beat Frequency