Hearing Science Exam 2

What is refraction

Sound bends in a new medium

Diffraction

Sound bends around obstacles

Interference

when soundwaves overlap each other

Constructive interference

if both waves are at same point in cycle they reinforce eachother

Destructive Interference

if two waves are at different phases they work against each other

Quarter Wavelength Resonator Formula

finding resonant frequency of a tube open at one end and closed at the other

spectrogram

x time y frequency

spectrum

x frequency y intensity

waveform

x time y intensity

bandwidth

freq ranging from lowest to highest

colors of noise

white purple pink red blue black

resonant freq

built up amplified

harmonic

integer multiples of fundamental freq

what makes pure, sine, noise, square waves different?

square are complex, periodic, cont so are sawtooth and white noise

Interaural intensity difference

sound at second ear is further from sound source

Interaural time difference

time difference sound wave travels from one ear to the other

Transducer

change signal from one type of energy to another

three parts of electroacoustic chain

receiver, signal processor, transmitter

difference between acoustic and audio signals

audio is stored reproduced version of original acoustic signal

output-input

= gain

required for sound to be present

elastic medium, vibrating object, energy source

human range of hearing

20-20k Hz

human range of speech

250-8k Hz

Fourier analysis

breaking down a complex sound to show all frequencies

fundamental frequency

lowest frequency present

frequency most likely to diffract

low frequency

frequency most likely to reflect

high frequency

reverberation

relfected sounds overlap each other

echo

reflected sound doesnt overlap in time

effects sound reflection

stiffness, density, surface area