Chapter 11 Flashcards
sound
physical (sound is what a person senses during hearing through pressure changes occurring in the ears ; environment)
perceptual (sound is what the person experiences, perceived, or interprets during hearing)
sound waves
pattern of air pressure moving or vibrating
compression
when sound first comes out, there is an increase of air pressure in the atmosphere
rarefaction
when air pressure spreads out in the atmosphere, there is a decrease in air pressure
how do sound waves travel?
air pressure from air molecules does not just go outward
they vibrate back and forth in a certain way at a location and stay about the same place for that location
frequency
number of cycles within given time period
measured by Hertz
tone
amplitude
difference in pressure between high and low peaks of wave; size of the air pressure
measured by decibels (0 dB - can’t hear anything ; 120 dB - extremely loud, can cause damage)
loudness
timbre
our ability to detect differences of sound not due to loudness, pitch, or duration
outer ear
pinnae (helps identify locations of sound)
auditory canal (protects tympanic membrane; resonance - amplifies sounds’ frequency b/w 1000 - 5000 Hz)
tympanic membrane
middle ear
2 cubic centimeter cavity
ossicles (amplify air pressure changes when sent to ear fluid):
malleus (hammer) - attached to ear drum, moves due to sound vibration
incus (anvil) - sends vibration to stapes
stapes (stirrup) - sends vibration to inner ear via oval window of cochlea
middle ear muscles (help us perceive sound from environment without sound of own voices or chewing)
inner ear
has cochlear fluid
cochlear (fluid-filled structure set into vibration by stapes)
cochlea uncoiled:
cochlear partition (organ of corti that contains cilia) separates scala vestibule (upper) and scala tympani (lower)
in organ of corti:
basilar membrane (bottom; moves up and down when fluid vibration occurs)
tectorial membrane (top; slides back and forth)
