Hearing Science Final

3 requirements for sound

energy source vibrating object elastic medium

period

time it takes to complete one cycle

Wavelength λ

physical distance in space traveled during one period of a wave

frequency

number of cycles per second

intensity or amplitude

Change in magnitude of wave

Phase

point in cycle

density property of medium

closeness of particle spacing at equilibrium

stiffness property of medium

elasticity or opposition to particle motion

absorption

sound is absorbed

reflectance

sound is reflected

refraction

sound bends in a new medium

diffraction

sound bends around obstacles

interference

what happens when soundwaves overlap each other

doppler effect

higher pitch when sound moving towards you lower when moving away

spectrum

x frequency y intensity

spectrogram

x time y frequency

waveform

x time y change

5 facts about dB

relative ratios reference non linear logarithms

0 db

equal to reference value

different types of complex sounds

sawtooth square triangle

five parts of ear

outer middle inner auditory nerve cans

outer ear functions

protect middle/inner ear collect sound emphasize frequencies

middle ear functions

protect the inner ear transform sound pressure equalization

c in cslim

cochlear nucleus

s in cslim

superior olive

l in cslim

lateral lemniscus

i in cslim

inferior colliculus

m in cslim

medial geniculate

binaural cue interaural time difference

time difference for sound wave to go from one ear to another

binaural cue interaural intensity difference

sound at second ear is further from sound source, results in less intensity of sound

what is a transducer

change a signal from one type of energy to another

3 parts of electroacoustic chain

receiver signal processor transmitter

audio vs acoustic signal

audio signals are stored reproduced version of the original acoustic signal

acoustic head shadow effect

if barrier to sound is a head