beats: beats is When two sound waves of different frequency approach your ear.when two tones of slightly diffrent frequencies are sounded together.
compression: in mechanics, the act of squeezing material and reducing it's a volume. in sound, a pulse of compressed air or other matter opposite of rarefaction.
force vibration: the vibration of an object that's made to vibrate by anther vibrating object that's nearby. the sounding board in a musical instrument amplifies the sound through forced vibration.
infrasonic: term applied to sound pitch too low to be heard by the human ear, that's below 20 hertz.
natural frequency: A frequency at which an elastic object, once energized, will vibrate. minimum energy is required to continue vibration at that frequency. also called resonant frequency.
pitch: Term that refers to how high or low sound frequencies applear to be.
rarefaction: a disturbance in air or matter in which the pressure is lowere.
resonance: resonance is the tendency of a system to oscillate with greater amplitude at some frequencies than at others.
ultrasonic: Ultrasonic is an adjective referring to ultrasound.