PSY-3215 Lecture Notes - Lecture 24: Sine Wave, Hearing Range, Sound
Document Summary
Diagram of a sound wave (diagram) is a sine wave. Compression: air molecules are above normal pressure (increase in air pressure) Rarefaction: air molecules are below normal pressure (decrease in air pressure) Hearing range 20 hz - 20,000 hz. As you go below 20 hz, the single note breaks up. All sounds combine together when entering the ear, and it is the job of the hearing system to deconstruct those sounds and determine what noise belongs to what object. Amplitude: height from resting air pressure to the top of the wave. Each step of 20 db means that the amplitude has increased/decreased by a factor of ten. An increase at 6 db is a double of amplitude (double the sound intensity) Phase angle: location within the wavelength cycle. Think of it like a circle begin at 0 , quarter way 90 , halfway through the cycle. 180 , three-quarters way through the cycle 270 , return to starting position.
