PSY280H5 Study Guide - Final Guide: Sound Pressure, Tonotopy, Sensorineural Hearing Loss
Document Summary
Two definitions of sound: physical: sound is pressure changes in the air or other medium, perceptual: sound is the experience we have when we hear. Amplitude/loudness is determined by sound pressure level: difference between high and low peaks in sound wave. Air pressure changes move outwards, but air molecules move back and forth (stay at same place: sound pressure level is expressed in decibels (log scale) increasing the sound level by 10db almost double"s the sounds loudness. 0 db = relative amplitude 1 quiet midnight. Above 140 db will harm/damage inner ear. Frequency/pitch has an audible range (humans) of 20-20,000 hz: number of cycles per second the change in pressure repeats. Higher frequency = higher pitch: tuning fork causes periodic condensation and rarefaction of air molecules. Auditory nerves are only equipped to conduct specific frequencies and not complex wave patterns.
