Audiology Flashcards
neuroplasticity
the ability of a baby’s brain to change with learning
synaptic pruning
- unused or weak connections are eliminated
- strong connections are strengthened
when do babies with typical hearing start hearing
20 weeks
ears function
- transmit and transduce sound to the brain
- maintain balance
brain
true hearing organ
optimal time for auditory neural connections to form
first 3 years
babies born with hearing loss
- missed 20 weeks of typical development of the auditory brain before birth pathways before birth
- missed auditory neural development after birth and that would have happened with hearing aids
0-4 months (hearing milestones)
- startle to loud sounds
- sensitive to a wide range of sounds
- quiet to familiar voice
4-6 months (hearing milestones)
- localize sound
- angry v. friendly voices
- like sound-making toys
6-12 months (hearing milestones)
- turn to mother’s voice
- repeat sounds
- respond to their name, “no-no”, and “bye-bye”
12-18 months (hearing milestones)
- imitate spoken words
- word approximation (dog = ruff ruff)
- jabber in response to human voice
- understand ~50 words
18-24 months (hearing milestones)
- understand simple sentences
- echo prominent/last words spoken
- use 10-15 words by 24 months
24-30 months (hearing milestones)
- understand and answer yes/no questions, simple “wh-“ questions
- listen to simple stories
- follow simple directions
30-36 months
- understand nearly all sentence types
- communicate effectively with strangers
- understood by others
parts of the ear
- outer ear
- middle ear
- inner ear
auditory path
sound waves travel from the outer ear → auditory canal (causes ear drum or tympanic membrane to vibrate which causes ossicles to move) → oval window → fluid in cochlea and inner ear (vibrations into electrical impulses) → brain
outer ear features
- pinna
- auditory canal/meatus
- tympanic membrane (eardrum)
pinna
- cartilage and soft tissue
- only visible part of the ear (auricle)
- localization
pinna function
- direct sound into the ear (without it, sound would be lost making it harder to hear)
- helps overcome pressure difference (air pressure higher in the ear)
- transition into the auditory canal smoother
auditory canal
- transmit sound from the pinna to the eardrum
- natural hearing aid (amplifies low sound, compensate for human voice weakness)
tympanic membrane
- sensitive membrane at the end of the auditory canal
- pressure from sound waves makes the eardrums vibrate
- marks beginning of middle ear
- slightly curved to make it difficult to insets to get in
- earwax
earwax function
keeps dust, dirt, and insects out
middle ear features
- ossicles (malleus, incus, and stapes)
- oval window
- round window
- eustachian tube
middle ear function
acoustic transformer (amplify sound waves before moving them to the inner ear)
pressure on oval window is ___ higher than the eardrum
20x
ossicles
- malleus
- incus
- stapes
ossicles form a _____ from the _______ to the _____ ___
chain, eardrum, inner ear
oval window
a membrane covering the entrance to the cochlea in the inner ear
round window
- vibrates in opposite phase to vibrations entering the inner ear through the oval window
- allows fluid in the cochlea to move
eustachian tube
connects ear to rearmost part of the palate
eustachian tube function
equalize the air pressure on both sides of the eardrum ensuring that pressure doesn’t build up
how does eustachian tube pressure equalize
tube opens when swallowing allowing pressure to equalize
what happens if ear pressure is not equalized
limited vibrations result in a slight hearing reduction
inner ear features
- cochlea
- semicircular canals
inner ear function
hearing and balance
cochlea function
responsible for hearing
cochlea
- bony, looks like a snail with fluid and hair cells inside
how ear bone motion turns into understandable sound
- when middle ear bones move, fluid in the inner ear moves which triggers hair cells (different hair cells move for different sounds)
- hair cells turn movement into electrical signals which go to the brain via the auditory nerve and the brain deciphers the sounds
semicircular canals
part of the balance system
ascending auditory pathway
the central auditory nervous system
anatomy of the auditory periphery
how the basic sound attributes are coded within the auditory periphery
where do fibers from the cochlear nuclei synapse
superior olivary complex
central auditory nervous system path
Fibers synapse on the cells of the cochlear nuclear complex → superior olivary complex (soc) → lateral lemniscus (some fibers synapse in the lemniscus but most travel through it) → inferior colliculus (ic) → medial geniculate body → auditory cortex
central role of the auditory cortex
processing of complex sounds
different neural types are responsible for information about ______ and ________ features of sound
spectral, temporal
auditory processing
the way our ears communicate with the brain and what the brain does with the information
auditory processing disorder
difficulty processing sound and speech with normal hearing
sound is described by _____________ and _____________
frequency, intensity
frequency
- the number of vibrations (sound waves)/second
- measured in Hz
what frequency can healthy young adults hear between
20 and 20,000 Hz
does the ability hear high frequencies increase or decrease with age
decrease
high frequency example
bird chirping
low frequency example
drum beating
intensity
- the amount of energy of a vibration
- measured in dB
intensity extremes can …
damage the ear
audiogram
a sound chart.graph that records a person’s hearing ability
thresholds
softest sounds/levels
tones
sounds
sounds on the left side of the audiogram are …
sounds on the right side of the audiogram are …
low pitch
high pitch
the lower you go on the audiogram, the _______ the sound is
louder
normal hearing
15dB (child) or 20 dB (adult)
minimal hearing loss and what they can’t hear
- 16-25 dB
- can’t differentiate between “f” and “th”
mild hearing loss
24-40 dB
moderate hearing loss and clinical symptom
- 40-55 dB
- soft speech is inaudible, normal conversation is a whisper
moderate to severe hearing loss
- 55-70 dB
- most (if not all) conversational speech is inaudible
severe hearing loss
70-90 dB
profound hearing loss, what can’t be heard
- > 90 dB
- conversational and environmental sounds are inaudible
treatment options for hearing loss
- surgical intervention
- amplification/cochlear implants
- early intervention (for communication and development)
possible multidisciplinary team members
- parents
- audiologist
- SLTs, OT, ENT
- teachers
- psychologists
- physiotherapist
hearing (at home training)
- contrast sound and silence (music on/off)
- make sounds together (noisy toys and voice)
- everyday voice
awareness (at home training)
- body sounds (cry, cough, sneeze, laugh)
- verbalize sounds (bad cough, shakey shakey)
- play with ling 6 voice sounds (mmm…nice, sh….quiet, ssss..snake)
attention (at home training)
- focus on something long enough to make sense
- look and listen, respond consistently to sounds
- everyday sounds (telephone, dog)
- tone of voice
listening (at home training)
- recognize familiar sounds, words, songs
- hanen approach (owl: observe, wait, listen)
understanding (at home training)
- copy and clarity and add language
- comment on what is happening
- follow instructions
- play
turn-taking (at home training)
- take turns using voice
- translate sound/babble into meaningful words
- praise and imitate early sounds
talking (at home training)
- first words –> expand vocab
- work on clarity when reading (c-a-t)
- phonological awareness (e-le-phant)
- offer choices instead of yes/no questions
- model please and thank you
apd diagnostic steps
- Rule out peripheral auditory involvement with a comprehensive hearing test (with acoustic reflex)
- Rule out attention deficits, memory, and IQ disorders
- Rule out language disorder
- Diagnostic Audiological Assessment battery
[Comprehensive hearing test (w/ acoustic reflex), Auditory discrimination word list, Degraded speech signals (filtered words, rapid speech, and speech-in-noise), temporal processing (frequency, duration, and gap detection), dichotic/binaural listening (integration/separation)]
apd manifests as poor:
- Localization and lateralization
- Auditory discrimination
- Auditory pattern recognition
- Temporal processing
- Performance with competing or degraded acoustic signals
apd treatment
- environmental/classroom modification
- teacher-directed strategies
- fm system or low-gain hearing aids
- strengthen general language skills
- auditory training
signs of hearing loss
- no response to sound at any age
- infant does not move or jump with loud noise
- no babbling by 9 months
- no works spoken by 18-24 months
- does not follow simple commands by 2 years old
- visually oriented
types of hearing loss causes
- idiopathic
- congenital (acquired or genetic)
idiopathic
- an underlying, unidentifiable cause
- 70% of all hearing loss
- most children born with a permanent congential hearing loss are born to normal hearing parents
causes of acquired congenital hearing loss
- maternal infections (syphilis, toxoplasmosis, rubella, CMV, herpes)
- drug/alcohol use during pregnancy
- maternal diabetes
- high blood pressure in pregnancy
- premature birth, low birth weight, birth injury
- raundice
- anoxia
causes and % of genetic hearing loss
- 50% of hearing loss
- hearing loss after an environmental infection, trauma, etc.) is influenced by genes
- sometimes related to a syndrome
- recessive mutation
autosomal dominant
- 50% chance of being affected
- individual in each generation are affected
autosomal recessive inheritance
- 25% chance of being affected
- 66% chance the unaffected offspring is a carrier
- one parent is a carrier
causes of acquired hearing loss
- infections
- middle ear problems
- trauma/aging
- loud noise exposure
conductive hearing loss
- related to disease or deformity
- normal bone conduction thresholds are <20 dB and an air-bone gap of >15 dB
causes of conductive hearing loss
- ear canal obstructions
- perforations
- otitis media
- otoscerlosis
- cholesteomtoma
- atresia
- microtia
sensori-neural hearing loss
related to disease or deformity of the inner ear/cochlear nerve
causes of congenital sensori-neural hearing loss
- genetic
- nongenetic causes (virus, infection, etc)
causes of acquired sensori-neural hearing loss
- genetic (cochlear otosclerosis, syndromic hearing loss)
- nongenetic (meningitis, ototoxicity, noise induced hearing loss, chronic middle ear problems, etc.)
mixed hearing loss
- conductive and sensori-neural hearing loss (conductive overlay)
- otosclerosis
mixed hearing loss causes
- chronic middle ear problems
- cholesteomtoma
- otosclerosis
unilateral hearing loss
- localization difficulties, turning to one side in order to hear, poor hearing in ambient noise
- 10x more likely to experience academic failure, 5x more likely to experience academic difficulty
causes of unilateral hearing loss
- CMV
- meningitis
- mumps
- auditory neuropathy spectrum disorder
- sudden sensori-neural hearing loss
- enlarged bestibular aquect syndrome
- prematurity
- trauma
auditory neuropathy spectrum disorder
- outer hair cell function in the cochlea is normal but inner hair cell or the auditory nerve function is disrupted
- affected neural processing of auditory stimuli
- difficulty understanding speech in noisy settings
- respond to sound appropriately but decoding speech/language is hindered
- auditory brainstem response absent or severely hindered at high stimulus levels
- otoacoustic emissions and or cochlear microphonic present
causes of auditory neuropathy spectrum disorder
- history of anoxia, hyperbilirubinemia, mechanical ventilation, hypoxia
- congenital brain abnormalities
- extreme premature birth or low birth weight
- viral disease, high fever
- seizure/neurological disorders
causes of apd
- CNS tumors
- premature or low birth weight
- extrinsic brain damage
- delayed maturity of central auditory pathway
- metabolic disorder
- epilepsy
- auditory deprivation
- periods of hearing loss
- glue ear (OME)
greater the hearing loss and the earlier it was…
the less intelligible the speech
hard of hearing children tend to be _______ rather than _________
delayed, deviant
newborn hearing screen
- automated otoacoustic emission (AOE)
- automated brainstem test if aoe fails
automated otoacoustic emission (AOE)
- shows ear hair cells are reacting in response to a noise
- can pass with mild hearing loss (looking for moderate to severe hearing loss)
- 3 out of 5 checks = pass
automated brainstem test
- last newborn hearing screening
- child asleep for 30 minutes
- specific waveform that moves with sounds (flat line = deaf)
- normally a sensori-neural hearing loss
which children automatically receive AOE and AABR
children in NICU > 48 hours
management of failed newborn hearing screen
- middle ear fluid testing
- full auditory brainstem response tests
- diagnose a permanent hearing loss with degree
intervention for newborn who fail the hearing test
- hearing aid (mild to moderate hearing loss)
- cochlear implant (severe to profound hearing loss)
- bone anchor implants (conductive hearing loss)
when to refer a child for diagnostic hearing assessment
- failed hearing screen
- delayed speech
- poor pronunciation or omitting start/end of words
- poor balance/sensory
- repeated middle ear infections
- bad genes
- parental concerns
hearing tests
- tympanometry
- otoacoustic emissions
- pure-tone audiometry
- audiometry
newborn hearing test facts
- objective
- little to no cooperation
infant (<2 years old) hearing test facts
- game played
- no earphones, lots of assuming
older child (<2 years old) hearing test facts
- objective
- earphones used
speech discrimination pass
25 dB
types of hearing loss
- permanent minimal and bilateral mild hearing loss
- unilateral hearing loss
- moderate to profound sensori-neural hearing loss
- temporary/fluctuating conductive hearing loss
primary cause of permanent minimal and bilateral mild hearing loss
otitis media
is parental suspicion likely in permanent minimal and bilateral mild hearing loss
no, may have subtle language problems, reading difficulty, and behavioral problems instead of extreme hearing difficulty signs
permanent minimal and bilateral mild hearing loss
- problem hearing fain/distant speech, subtle conversation, fast conversation, and word distiction (plural and possessive)
- more obvious in children with additional problems
distance hearing
- the distance over which speech sounds are intelligible (not just audible)
- any hearing loss reduces distance over which speech sounds are intelligible even with amplification
passive hearing
- eavesdropping
- hard of hearing people cannot casually overhear what people are saying
- learning of social skills is affected
hearing loss symptoms on speech and language development
- delayed canonical babbling
- no auditory feedback loop
- prelinguistic and early language development stunted
_________ and ____________ are vulnerable to omission and substitution with all degrees of hearing loss
fricatives, affricatives
moderate to profound sensori-neural hearing loss
- incomplete access to speech
- hearing aids bring much speech into the audible range
- discriminate between consonants by voicing and manner
- difficulty identifying syllabic boundaries and speech pattern with hearing loss >95 dB
temporary/fluctuating conductive hearing loss
- speech and language difficulties due to developmental period during which the fluctuating hearing loss occurred
- spatial orientation difficulty
chronic otitis media symptoms that last for 8+ weeks consecutively are at risk for ….
speech and language problems
vocal learning
hearing, production of sound, and relating the two together
pre-lingual effects of hearing loss in adults
impact development of spoken language, reading ability, educational attainment, and vocational potential
post-lingual effects of hearing loss in adults
cognitive and competency skills are unaffected when the hearing loss occurs slowly
why is hearing loss related to dementia
greater cognitive resources dedicated to auditory perception processing detrimental to other cognitive processes (memory)
