hearing anatomy Flashcards
what is the function of the outer ear
conducts sound and directs to ear drum
role of middle ear
absorbs sound and transmits vibrations through ossicular chain
eustachian tube
equalizes pressure between middle ear and external air
allows drainage
inner ear components
bony labyrinth includes vestibule, semicircular canals and cochlea
membranous labyrinth includes utricle, saccule, cochlear duct
utricle and saccule
balance
how is sound converted into electrical signals
stapes footplate displaces cochlear fluids causing basilar membrane to move disturbing hair cells which transducer mechanical energy into electrical impulses
what does the outer ear do
transmit sound waves to middle ear
middle ear
converts sound waves into mechanical energy
inner ear
converts mechanical energy into electrical energy
presbycusis
age related hearing loss
usually sensorineural
phonemic regression
significant reduction in speech discrimination
recruitment in hearing loss
abnormal increase in perceived loudness of auditory signal
tinnitus
ringing sensation
how does aging affect outer ear
minimal documented changes affecting hearing
how does aging affect middle ear
less efficient at sound transmission due to stiffness
how does aging affect inner ear
damage to hair cells leading to presbycusis
conductive HL
outer or middle
sensorineural HL
inner or nerve
discrimination
telling differences between sounds or stimuli
how is conductive hearing loss treated
medically or surgically
tubes or antibiotics
how is sensorineural hearing loss treated
hearing aids
cochlear implants
aural rehab
speech reading
what are the responsibilities of audiologists
hearing measurement, diagnostic assistance, medical rehab, aural rehab
why dont older adults always receive audiologic help
availability, awareness and cost are major barriers
what factors affect the success of audiological habilitation
training in hearing aid use, physical and psychological barriers, memory issues, family reactions, financial concerns, relocation, and health problems
what is the purpose of pure tone air conduction testing
measure the hearing threshold for sounds transmitted through air
what is the difference between pure tone air conduction and bone conduction testing
shows if there is a conductive component to HL
What does speech recognition threshold testing measure?
SRT measures softest level that a person can correctly repeat two syllable words with 50% accuracy
speech discrimination testing
persons ability to repeat 25-50 one syllable words
what does impedance testing check
status of middle ear by assessing how ear reacts to air pressure change
what is brainstem evoked response audiometry
uses EEG to check if sound reaches brainstem
what is electronystagmus testing
involuntary eye movements in response to vestibular stimuli
why is it difficult to test central auditory system
there are no reliable tests and central issues can affect all aspects of auditory behavior
