PSYB51H3 Lecture Notes - Lecture 9: Sound Pressure, Sine Wave, Tectorial Membrane
Document Summary
Vibrations cause molecules in the surroundings of object to vibrate as well causing pressure changes in medium. Speed of sound depends on the density of the medium. Amplitude: magnitude of displacement of a sound pressure wave. Sine wave representation of the pressure waves. Intensity: amount of sound energy falling on a unit area. Measured in decibels sound pressure level (db spl) Decibels: ration between the pressure of some sound and the pressure of a reference sound po (~ minimum) Loudness: the psychological aspect of sound related to perceived intensity or magnitude. Humans can hear a wide range of sound intensities. Ratio between faintest and loudest sounds is over 1 to one million, 6db = double amount of pressure. Frequency: for sound, # of times/ second that a pattern of pressure change repeats. Pitch: psychological aspect of sound related to the fundamental frequency. Human hearing uses a limited range of frequencies: 20 20,000 hz.
