MEDI7212 Lecture Notes - Lecture 44: Presbycusis, Neuroma, Salicylic Acid
Document Summary
Inner ear - cochlea (hearing), semicircular canals (angular acceleration) and internal auditory channel: cochlea and scc communicate at the utricle and saccule. Sound impulse creates a change in pressure (compression -> rarefaction of particles: vibrating source transmits energy from point of origin through a medium (liquid, solid, air) as a sound wave of variable wavelength. Frequency - number of vibrations or cycles per sec (hz) Low pitch sound has less cycles with longer wavelength: high pitch sound has more cycles with shorter wavelength, amplitude - loudness of sound (rate of energy transfer along the waveform) Sound intensity measurement: decibel (db) - loudness/ intensity/ sound pressure level, pascals (larger unit than db, ratio of the measured sound pressure to the lowest perceptible sound pressure. Increase in 3db ~ 2x sound intensity: example: play 2 identical machines that each record 90db together creates measured sound level of 93db.
