Week 9 Physics of Sound and Hearing Flashcards
define sound
vibration that travels through an elastic medium as a wave
give the 4 phenomena that affect sound propagation
refraction
reflection
diffraction
scattering
what kind of wave is sound
longitudinal
what is the doppler effect
an increase in frequency of waves as the source and observer move closer together and a decrease as they move away
what is sonic boom
when a sound source is travelling at the speed of sound in that medium an observer in front of the source will not hear the source until after it passes
what are overtones
the frequencies other than the fundamental ones that exist in musical instruments
what is Helmholtz resonance
phenomena of air resonance in a cavity
what is an example of Helmholtz resonance
blowing over the top of an open bottle leads to wind chime sound
what is the threshold of hearing and its associated value for humans
faintest intensity of sound a human ear can hear
human have a threshold of 1x10^-12
how do intensity and loudness of a sound differ
intensity is an objective quantity whereas loudness is a very subjective quantity
what are the 3 properties of sound we can perceive and how
1 pitch - detecting frequency
2 loudness - detecting amplitude
3 timbre - detecting various frequencies of a complex sound
what is function of the outer ear
collect sound waves and channel it to the middle ear
what is the function of the middle ear
transform sound wave energy into internal vibrations of the bone structure that are transformed into compressed wave for the inner ear
what is the function of the inner ear
transform energy of a compressed wave into a nerve impulse which is transmitted to the brain
