PSYB51H3 Lecture Notes - Lecture 9: Auditory Cortex, Axon, Tectorial Membrane
Document Summary
What is sound: sounds are created when objects vibrate. Vibrations of object cause molecules in object"s surrounding medium to vibrate as well, which causes pressure changes in medium. Speed of sound depends on density of medium. Amplitude: magnitude of displacement of a sound pressure wave. Intensity: amount of sound energy falling on a unit area. Measured in decibels sound pressure level (db spl) Decibels: ratio between the pressure of some sound and the pressure of a reference sound p0 (~minimum). Db = 20*log(p/p0); e. g. 20*log(2) = 6. Loudness: the psychological aspect of sound related to perceived intensity or magnitude. Intensity of environmental sounds: humans can hear across a wide range of sound intensities. Ratio between faintest and loudest sounds is more than one to one million, 6db = double amount of pressure: basic qualities of sound waves (cont"d) Frequency: for sound, the number of times per second that a pattern of pressure change repeats.
