WSU AUD 5420 week 1 intro, anatomy, audiogram, immittance

aural rehabilitation

treatment of persons with adventitious hearing impairments to improve the efficacy of overall communication ability, including the use of hearing aids, auditory training, speech reading, counseling, & guidance

goals of aural rehab

identify the difficulties related to the hearing loss; provide appropriate technical support to minimize consequences, training people to understand speech & language in the real world

14-40 million people

number of people in the US with significant hearing loss

10% of the US population

has some degree of hearing loss

3 million children per year

are diagnosed as deaf or hard of hearing

most common congenital sensory impairment

hearing loss

external auditory meatus

ear canal

meatus

canal within a bone

otoscope

lighted hand-held instrument used for visual examination of the ear canal & tympanic membrane

otoscopy

evaluation of the ear canal to ensure it’s not blocked with wax or foreign object; to look for abnormalities in the ear canal, TM, eardrum, possible infections

cone of light

a light reflection observed in the anterior inferior quadrant of the tympanic membrane through a lighted otoscope

cone of light in right ear

approximately 5 o’clock

cone of light in left ear

approximately 7 o’clock

middle ear ossicles

malleus, incus, stapes

tonotopic organization of the cochlea

high frequencies at the base to low frequencies at the apex

hearing evaluation

finding & plotting air and bone conduction thresholds at tested pure-tone frequencies to determine degree, configuration, and type of hearing loss

hearing threshold

the softest sound level at which a person can hear a stimulus at least 50% of the time on ascending presentations

speech recognition threshold (SRT)

the lowest/softest intensity level at which 50% of stimuli (spondee words) can be correctly identified; measured as a threshold

word recognition score (WRS)

the ability to correctly repeat phonetically balanced words (single syllable words that contain speech frequency sounds); measured as a percentage

characteristics of hearing loss

degree, configuration (shape), type, time of onset relative to birth and speech/language development, causes

normal hearing

less than or equal to 20 dB HL

mild hearing loss

20-40 dB HL

moderate hearing loss

40-55 dB HL

moderately-severe hearing loss

55-65 dB HL

severe hearing loss

70-85 dB HL

profound hearing loss

equal to or greater than 90 dB HL

air-bone gap

difference between air conduction threshold and bone conduction threshold at a given frequency of a test ear, measured in dB; difference shows middle or outer ear issues

sensorineural hearing loss

confined to the inner ear; no air/bone gap; hair cells/cilia are damaged after prolonged loud noise exposure

symptoms of sensorineural hearing loss

perceiving speech and other sounds are distorted or unclear, difficulty hearing certain pitches (usually high), may experience tinnitus, difficulty understanding speech in the presence of background noise, pt will often say ‘I can hear, just not clearly’

conductive hearing loss

results from blockage, damage, or disease to the outer and/or middle ear, with normal cochlear function; includes an air/bone gap of 15 dB or more, with bone conduction in the normal range

symptoms of conductive hearing loss

perceiving speech and other sounds as faint or muffled, may have ear pain or discharge from ear, redness or swelling of outer ear, pts may report pressure or fullness in the ear

causes of conductive hearing loss

infection of ear canal or middle ear, fluid in middle ear, perforation or scarring of eardrum, wax build-up, unusual growths or tumors in ear, otosclerosis (abnormal growth of bone of the middle ear)

mixed hearing loss

conductive hearing loss and sensorineural hearing loss, air/bone gap of 15 dB or higher, bone conduction threshold below normal

why do we test bone conduction

to determine if the type of hearing loss is conductive, sensorineural, or mixed

crossover

when sound presented to the test ear through a transducer crosses over to the non-test ear via the skull (bone conduction)

cross hearing

when sound that crosses over the the non-test ear is heard by the non-test ear

masking

removes the non-test ear from the testing situation by presenting narrowband noise, prevents patient from responding to a stimulus perceived by non-test ear and allows for evaluation of the test ear

central auditory processing disorder (CAPD)

normal hearing sensitivity or hearing worse than expected from audiometric eval results; normal function of outer, middle, and inner ear, cannot appropriately process the info they hear (background noise is an issue), occurs in children & adults

auditory neuropathy

sounds enter the inner ear normally but there is an issue with neural synchrony (like an out of sync choir); hearing function greatly varies