Audition Flashcards
(23 cards)
Basilar Membrane
Contains hearing receptors. Varies in length across species
Sound waves
initiated by vibration and interact with ear drum to begin sound processing
Amplitude
Affects loudness. Higher waves=louder sounds. Loudness measured in decibels
Wavelength
Affects pitch. Shorter wavelength=higher pitch. Measured in Hz
Purity
Purity indicates timber
Timber
Timber is complexity of sound
External Ear
Pinna, Auditory Canal, Ear Drum
Pinna
Your “Ear”
Auditory Canal
Amplifies sound
Ear Drum
Thin membrane vibrating at frequency of sound wave and forms back wall of ear canal
Middle Ear
Ossicles
Ossicles
Hammer, anvil, stirrup. Amplify sound since they are larger than the oval window they connect to. Amplification necessary because change in air pressure about to be converted to waves of fluid.
Inner Ear
Cochlea
Cochlea
Contains tissues necessary to change the changes in fluid to neural impulses. Snail like
Basilar Membrane
Runs length of cochlea separating oval window. Gets wider towards end of cochlea which requires low frequencies to vibrate
Hair Cells
release neurotransmitter when moved
Inner hair cells
Mainly responsible for transmission. Less numerous, but faster and have more than 20 direct links to brain. Help establish exact pitch of sound. Thick and myelinated
Outer Hair Cells
More numerous, but less connections to the brain and slower. Share one direct link to brain with approx. 30 other cells. Thin and unmyelinated
Tonotopic Organization
Organized by frequency
Auditory Localization (Close Sounds)
Locate sounds by detectable loss of intensity since sound waves have to travel farther to reach one ear
Auditory Localization (Far sounds)
Rely on differences in intensity caused by the head (sound shadow)
Pinna Cues
Localize elevation of a sound source
Echolocation
Process by which receiver emits sound pulses and analyzes returning echo to form perceptual image of objects
