Ch 10 Audiology Flashcards
most complex division of the ear
INNER EAR IS THE MOST?
inner ear receives mechanical vibration of sound through the movement of the ?
stapes footplate in oval window in the temporal bone
TWO MAJOR STRUCTURES OF INNER EAR
1) vestibular system (semicircular canals)
2) cochlea
each ear contains X hair cells
about 15,500 hair cells!
middle ear and nasopharynx are connected by the X
eustachian tube - maintains pressure within and outside the middle ear
basilar membrane BM
is the floor of cochlea duct
tip of BM is
thick, wide, lax
LOW FREQ SOUNDS
base of BM is
thin, narrow, stiffer!
HIGH FREQ SOUNDS
high f sounds are stimulated at the X of the basilar membrane
BASE!
low f sounds are stimulated at the X of the basilar membrane
TIPq
simple harmonic motion
a tone of single f that repeats itself
ear can respond to frequencies X to X
20- 20,000 HZ!
normal speech SPL
50 to 70 dB SPL is normal X
pain dB SPL
140 dB SPL causes X
human ear MOST sensitive to sounds x-x
1000-4000 HZ
20 week old fetus responds to sound
TRUE
babies turn their head toward sound sources by X
3-4 months old
infant can localize soft speech / normal hearing infants have better hearing than adults
by 6 months of age
AIR CONDUCTION
sound strikes tympanic membrane - causing ossicles to move and fluid movement in inner ear
BONE CONDUCTION
fluids of inner ear housed in skull
bone conducts sounds to inner air
hearing loss levels MILD MOD MOD SEVERE SEVERE PROFOUND
up to 15 normal in kids 16-40 for kids 25-40 adults = MILD LOSS 41-55 = MOD 56-70= only understand shouted speech= MOD SEVERE 72-90= SEVERE 91+ is profound
Conductive loss
inner ear, AN, auditory brain centers normal
bone conduction normal - skull bones.
CHL is never profound because always some skull bone conduction happening….
Conductive loss
issue with sound to ME or IE
inner ear, AN, auditory brain centers normal
bone conduction normal - skull bones.
CHL is never profound because always some skull bone conduction happening….
otitis media creates X hearing loss
CHL= 20-35 dB HL
type of otitis media that permanent damage to middle ear structures occurs
chronic otitis media!
myringotomy- small incisions made to relieve pressure but in myringoplasty
perforated TM is repaired
Carharts Notch ( assoc. with conductive hearing loss of ME or IE)
found in those with otosclerosis (spongy growth on stapes footplate so no movement of inner ear fluid).
reduced bone conduction sensitivity at 2000 HZ!**
Carharts Notch ( assoc. with conductive hearing loss of ME)
found in those with otosclerosis (spongy growth on stapes footplate so no movement of inner ear fluid).
reduced bone conduction sensitivity at 2000 HZ!**
SNHL
damage to hair cells of cochlea OR AN prevents brain retrieval of sound impulses
bone and air conduction impaired in X hearing loss
SNHL
STORCH = major HL causes in fetuses
Syphilis Toxoplasmosis = through placenta Rubella = through placenta Cytromegalovirus - herpes type virus transmitted by close contact with infected kids Herpes simplex- mother to fetus
sloping of High freq SNHL
presbycusis
central auditory processing
effectiveness efficiency with which the CNS uses auditory information
difficulty understanding distorted speech
hallmark of issue with central auditory processing
AN tumor hearing loss
unilateral high f hearing loss
threshold
intensity level of tone heard at least 50% of time
fall in range of human speech
100-8,000 HZ
speech reception threshold SRT
lowest softest level of hearing at which person understands 50% of words presented. SPONDEE WORDS USED! equal stress on each syllable.
people with SNHL can hear but not understand speech
TRUE in speech discrim tasks (Repeating words)
impedance and admittance
impedance is the flow of energy
admittance is amount of energy that flows through system
aud. brainstem responses ABR help record X
electrical activity in auditory nerve- helpful for brainstem diseases.
hearing loss mild
16-40 dB
mod hearing loss
41-55 dB
mod- severe HL
56-65 dB
severe HL
66-89 dB
profound HL
90 + dB
air bone gap indicates a X loss
conductive loss - 10 dB or more !
postlingual deafness
HL after age of 5
hearing aids deliver
amplified sound to the ear canal
cochlear implant deliver
electrical impulses to the AN
SNR
the difference in dB between stim of interest ( teachers voice) to the competing background noise
cued speech is not sign language it differs because
8 signs for consonants and 4 for vowels - helps with homophenous sounds *(labial sounds look same but different)
sign and speech used simultaneously
TOTAL COMMUNICATION
