CSD Unit 3

Know the parts of the outer, middle, and inner ear.

• OUTER EAR:

• Pinna (auricle) - visible part that collects sound waves

• External auditory canal - passageway 

• Tympanic membrane (eardrum) - vibrates in response to sound 

• MIDDLE EAR:

• Ossicles (tiny bones) :

  • Malleus (hammer) - connected to eardrum 

  • Incus (anvil) - middle bone that connects malleus and stapes

  • Stapes (stirrup) - pushes on the oval window of the inner ear 

• Eustachian tube - connects the middle ear to back of throat 

• INNER EAR:

• Cochlea - spiral shaped organ for hearing; converts vibrations into neural signals 

• Vestibule - central part, helps with balance 

• Semicircular canals - three looped structures, detect balance 

• Oval window - membrane that receives vibrations from the stapes 

• Round window - relieves pressure in cochlea 

• Auditory nerve - carries sound info from cochlea to brain 

Which cranial nerve is primarily involved in hearing?

the vestibulocochlear nerve - transmits sound signals from the cochlea to brain

How is the frequency of a sound measured?

measured in hz - most important frequencies for speech are 250 - 5000 hz

How is the intensity of a sound measured?

Decibels

normal convo= 50 dB

What is the range for normal hearing

0-20 dB

20-20,000 hZ

sounds above 120 dB cause hearing loss

What is the range of decibels necessary for the development of normal speech and language?

0-20 dB

What is the range of frequencies for understanding speech?

250 - 5000 hZ

8. How do we differentiate a person who is deaf from a person who is hard of hearing?

hard of hearing includes any hearing loss from 21-89 dB where anything over 90 dB is deaf

3 general categories of hearing loss

conductive hearing loss - within the outer and inner ear, air bone gaps are PRESENT, air conduction is over 10 dB worse than bone conduction and bone conduction must be normal (normal bone conduction between 0 and 25 dB

sensorineural hearing loss - within inner ear, absence of air bone gaps, not usually correctable by medical intervention

mixed hearing loss - involves outer and inner ear - any conductive hearing loss with underlying sensorineural component (there is a presence of air bone gaps but bone is no longer in normal range… and air conduction is always greater than 20 dB)

air bone gap

difference in dB between air conduction and bone conduction thresholds on an audiogram (when present indicates conductive hearing loss)

otitis media

middle ear infection caused by fluid buildup behind the eardrum

common in children ; can cause temporary hearing loss

myringotomy

surgical procedure to drain fluid from the middle ear and relieve pressure, often performed in cases of recurrent otitis media

presbycusis

age related sensorineural hearing loss for high frequencies

often bilateral, gradual and affects clarity of speech

can be treated with a hearing aid

feature observed with a noise induced hearing loss

noise induced hearing loss = high frequency sensorineural hearing loss

max hearing loss at 4000 Hz

ringing in ear, muffled sound, pressure

difference between vertigo and tinnitus

vertigo = sensation of spinning or imbalance (inner ear or vestibular problem)

tinnitus = ringing or buzzing in ears without an external source

purpose of newborn infant hearing screening and intervention act

ensures early detection and intervention for infants with hearing loss

goals = screen by 1 month, diagnose by 3 and intervene by 6

behavioral observation audiometry

for infants - 6 months

observes baby reactions (head turn, eye widening, startle) to sounds

visual reinforcement audiometry (VRA)

6 months - 2.5 yrs

child turns head toward sound and is rewarded with visual stimulus

checks to see if they can localize sound and uses classical conditioning

conditioned play audiometry (CPA)

2.5 - 5 yrs

child plays a game (ex: drop block in bucket) when they hear a sound

physiological hearing tests

otoacoustic emissions

auditory brainstem response

tympanometry (pressure inserted into ear which produces a graph showing how well middle ear is getting sound from eardrum to inner ear)

how is hearing formally tested

audiometers (screening audiometer used in schools, diagnostic audiometers used in hospitals or clinics)

air conduction vs bone conduction testing

air conduction = pure tone presented which identifies hearing loss, however does not localize the problem

bone conduction = pure tone presented through bone oscillator, bypasses outer and middle ear and stimulates inner ear directly

if bone conduction responses are better than air conduction the loss is in the outer/middle and if bone conduction responses are equal to air the loss is a problem in the inner ear

air conduction tells us if hearing loss is present, bone conduction tells us what type of hearing loss

air bone gaps

when air conduction is 10x worse than bone conduction (usually correctable by medical intervention)

Tympanometry shows the movement of what structure?

the eardrum (tympanic membrane) as it assesses the middle ear pressure

Why would ABR be used with an infant?

ABR (Auditory Brainstem Response) is used with infants as it is more reliable than asking them to follow instructions to which they can’t listen to. it measures the brains response to sound without asking for specific behaviors

Know at least three signs to red flag a potential hearing problem.

delayed speech development

no startle or response to a loud sound

frequent ear infections

inattention/withdrawal

Which audiometric results may predict successful use of a hearing aid?

mild to moderately severe sensorineural hearing loss

Know the types of hearing loss and the severity range based on decibel level.

0-20 = normal hearing

21-40 = mild loss

41-55 = moderate loss

56-70 = moderately severe loss

71-89 = severe loss

anything above 90 = profound

How do a conductive vs. sensorineural vs. mixed hearing loss differ?

conductive = outer/middle ear, air bone gaps PRESENT

sensorineural = inner ear, NO air bone gaps

mixed = both types combined

What types of hearing aids are best for infants/children?

body aid- clunky aid best for infants

behind the ear BTE - best for school aged kids as aid is coupled to ear via hook and tubing, is easier to manage and less prone to breakdowns however sticks out of ear

What type of hearing aid has the best quality?

In-the-ear (ITE) aids offer better sound quality and are customized to fit the ear

When would it not be appropriate to fit a person with a HL with a hearing aid?

when profound hearing loss is present (refer to cochlear implant)

medical contradictions

What level of hearing is needed for a person to develop language appropriately?

0-20 dB and 250-5000 Hz is needed for effective language development. This allows children to hear speech sounds clearly and learn to communicate effectively.

What are ALDs?

assistive listening devices designed to assist in communication (ex: amplified phone, baby cry or doorbell signaler)

Know the purpose of an FM system and what singal-to noise ratio means

FM system enhances a teachers voice over background noise and is designed to improve the signal to noise ratio SNR (eliminates background noise with teachers voice directly in students ear)

What are the requirements for candidacy of a cochlear implant?

profound sensorineural hearing loss in both ears (people born deaf)

6 months hearing aid trial

motivation

realistic expectations

normal structural anatomy

infants born deaf have more leeway

Know how the components of a cochlear impant is organized.

external: microphone, processor which converts signal and external receiver

internal: internal receiver, electrode array (tonotopically arranged - arranged based on where different frequencies are processed in the brain)

What factors improve the benefits of a cochlear implant?

adults who became deaf post lingually (after they learned how to talk)

when implanted at a young age

Know several syndromes described in class associated with hearing loss.

usher syndrome = childhood onset sensorineural hearing loss, balance issues

waardenburg syndrome = moderate to profound sensorineural hearing loss in one or both ears present at birth

treacher collins syndrome = hearing loss in outer and middle ear leading to conductive hearing loss

Know the different hearing disorders discussed in class

cauliflower ear - outer ear, damage to ear from repeated blows (boxer, wrestler)

microtia - outer era, usually unilateral, occurs more often in males, ear is caved in

anotia - outer ear, absence of pinna

otitis media - middle ear, ear infection, VERY (80%) common in children, treatment with antibiotics

chloesteatoma - middle ear, growth of epithelium tissue, increases in size slowly and can destroy surrounding bone

presbycusis - inner ear, gradual and irreversible decline in hearing

What do phonological awareness skills predict?

reading and literacy development

Characteristics of Developmental Language Disorder (DLD)

issues with reception, expression or both

difficulties learning the rules and form of language, registering different contexts for language, learning content-semantics, following multi-step directions, learning verb and pronouns, writing

Describe the earliest narrative children tend to use and why is this used to assess language?

scripts (expressing knowledge of a familiar event), recounts (telling about a personal experience in response to a question), accounts (telling about an experience without being asked), event casts (explaining facts or plans), fictionalized stories

What are the CPSE and CSE and what do they do?

committee on preschool special education = individualized family service plan, for children birth to age 3

committee on special education = committee on special education, for school aged children

How do expansions and extensions differ?

expansions are the adult’s mature version of the child’s utterance (ex: child says doggie eat, parent says yes, the dog eats)

extensions are adults semantically related comments on a topic the child says (ex: child says doggie eat, parent says, yes the dog is hungry)

Know how self-talk and parallel talk are different

self talk - clinician talks about what they are doing

parallel talk - clinician talks about what the child is doing and what the clinician is doing

How does Response to Intervention (RTI) work and what is the purpose of RTI?

four-tiered support system for students with disabilities and is needed to rule out other factors

class room intervention

enrichment

school based intervention team

CSE (committee on special education)

Which strategies help to facilitate language at the elementary and middle/high school level

mazes (repetition or reformulation of a story), narratives (story telling), recounts, accounts, eventcasts (relating past present or future events)