Lecture 5- Hearing Sensation Flashcards
hearing
nervous systems way of detecting the systematic movements of molecules through the air
sound waves
caused when something vibrates, causing a systematic pattern in the movement of air molecules
kinetic energy
transmitted through air molecules
longitudinal waves
sound waves that travel through the medium of air or water
transverse wave
propagating at right angles to the movement of molecules
frequency of a sound wave
function of the rate of vibration of the object that is moving
high pitched sounds
faster frequencies
low pitch sounds
slower frequencies
amplitude
function of changes in the amount of energy being propagated through the medium
loudness
pressure; force with which the wave pushes into objects around it
timbre
tone quality
- 2 sources create sound with same pitch and loudness, however they always sound different
Pinna
attached to skull by ligaments and muscles.
-not well developed in humans, are in other animals
- bumps and ridges help focus and direct sound toward ear canal
concha
deepest depression in pinna, leads directly to the ear canal, helps to focus and amplify sound waves
ear canal
tube that runs from the outer to middle ear
Tympanic membrane
eardrum
ossicular chain
3 smallest bones in body, malleus, incus, stapes
oval window
where the stapes attach to the inner ear. moves back and forth, causing fluids to shift back and forth
bony labyrinth
consists of central chamber called vestibule, 3 semicircular canals, cochlea
membranous labyrinth
inside bony labyrinth
perilymph
liquid high in sodium (-) low in potassium (+)
endolymph
low in Na, high in K+
organ of corti
transduction begins
place theory
differences in thickness of basilar membrane, shape of cochlea, nature of sound waves all allow different hair cells in cochlea to respond only to certain frequencies
hair cells
- don’t regrow once lost
- wear out with age, starting with high-frequency receptive cells
- can be damaged to long-term exposure to loud noise
