Hearing Impairment Flashcards
Hearing Loss
Disability
Culturally Deaf
Native language is sign language
Identify with the attitudes, traditions, values, and mores of deaf culture
Social identity – hearing loss is a difference NOT a disability
Hard of hearing as a difference
Speech is the primary means of communication
Individual chooses to construct their view of hearing loss
Congenital hearing loss
Present at birth or shortly after birth
Prelingual/Postlingual Hearing Loss
Prelingual loss – hearing loss present at birth or before speech and language have developed ( ~2 years of age)
~50% due to genetics
Postlingual loss – hearing loss occurs after speech and language development
The Speech Chain
Step 1: The speaker’s brain
The speaker organizes his/her message
What do you want to say; how do you want to say it
A complex process but takes seconds
Step 2: The speaker’s brain
The speaker formulates his/her message into language
Step 3: The speaker’s central nervous system The speaker’s brain sends neural impulses (signals) through the central nervous system to the muscles of: Respiration Phonation Articulation arms, hands, torso (for support), etc. Step 4: Sound waves Air flow from the larynx is constricted by the articulators creating pressure changes in the air surrounding the speaker’s mouth Intensity (decibels) amount of energy per unit of air Frequency (hertz) cycles per second These patterns of pressure changes are sound waves Pure tones – sound at one frequency Complex tones – have fundamental frequency, harmonics, and formants Sound waves travel through the air to reach the listener’s ear drum
The Speech Chain
Step 1: The speaker’s brain
The speaker organizes his/her message
What do you want to say; how do you want to say it
A complex process but takes seconds
Step 2: The speaker’s brain
The speaker formulates his/her message into language
Step 3: The speaker’s central nervous system The speaker’s brain sends neural impulses (signals) through the central nervous system to the muscles of: Respiration Phonation Articulation arms, hands, torso (for support), etc. Step 4: Sound waves Air flow from the larynx is constricted by the articulators creating pressure changes in the air surrounding the speaker’s mouth Intensity (decibels) amount of energy per unit of air Frequency (hertz) cycles per second These patterns of pressure changes are sound waves Pure tones – sound at one frequency Complex tones – have fundamental frequency, harmonics, and formants Sound waves travel through the air to reach the listener’s ear drum Step 5: The listener receives the sound waves The external ear receives the sound waves The middle ear converts sound into mechanical energy. The inner ear converts mechanical energy into electrical energy/signals. Electrical energy travels through the VIII cranial nerve (vestibulocochlear) to the auditory cortex. Step 6: The listener's brain The listener’s brain decodes the neural energy What brain structure? The speaker’s message is interpreted and received
Conductive Hearing Loss
Outer or middle ear dysfunction
Sound is softer
May be treated with medical or surgical intervention
Some causes:
Head trauma
Fluid in the middle ear
Perforated Eustachian tube
Otitis media
Can cause mild fluctuating hearing loss
May result in language delay
Sensorineural Hearing Loss
Damage/dysfunction of cochlea or VIII cranial nerve
Sound is softer and distorted (bc hair cells are tuned to specific frequencies; damaged cells no longer detect those frequencies)
Typically, can’t be medically or surgically corrected
Severity of hearing loss depends on location and number of damaged elements
Amplification may help with sound volume
Some causes:
Congenital – e.g., prematurity
Diseases – e.g., meningitis
Presbycusis
Mixed Hearing Loss
Combined conductive and sensorineural
Conductive component medically treated
Sensorineural loss persists
Central Auditory Processing Disorder – dysfunction in the brain’s ability to process auditory information (difficulty processing auditory information in the brain)
Diagnosed by an Audiologist
Speech-language pathologist is part of the multidisciplinary team
Academic challenges may be present
Hearing Assessment
Audiologist
Evaluates an individual’s hearing
Recommends and fits assistive listening devices
Speech Audiometry
Quantifies hearing threshold for speech
Speech Reception Threshold – minimum hearing level for speech
Recognize 50% of speech material
Used to confirm pure-tone results
Speech discrimination – repeat monosyllabic words presented at a comfortable listening level
Otoacoustic Emissions
Sounds emitted by the inner ear when the cochlea is stimulated by sound
The sound is measured by a probe inserted into the ear canal
The sound isn’t present with sensorineural or conductive hearing loss
Degree of Hearing Loss
Average of pure-tone thresholds at:
500, 1000, and 2000 Hz
Greater severity, greater the affect on communication
Age of onset
Children
Adults
Course of onset
Gradual
Rapid
Other factors
Hearing Aids
Types
Components:
Microphone
Amplifier
Receiver
T-switch
Direct audio input (DAI)
Behind the ear (BTE)
In the ear (ITE)
Canal aids
Body and eye glass aids
Bone conduction aids
Digitally programmable hearing aids
Pure Tone Audiometry
Pure-tone thresholds
Compares thresholds to normal hearing
Air conduction and bone conduction
Test frequencies of 125-8000 Hz
AudiogramAuditory Evoked Potentials
Records brain wave activity in response to sound
Used for site of lesion testing or when behavior prevents other testing
Auditory speech perception
Detect speech signal
Interpret acoustic/phonetic elements
Identify familiar patterns
Apply linguistic, paralinguistic, and situational information
May be improved through training
Encouraged for hearing aid users
Visual speech perception
Visual information improves speech comprehension
Speechreading and lip reading
Children with sensorineural or mixed hearing impairment (HI)
Development depends on:
Age of onset
Early vs. late
Audiometric configuration of hearing loss
Age of identification and amplification
Early vs. late
Amount and type of habilitation
Children with sensorineural or mixed HI:
Delay in babbling
Consonant substitutions and distortions
Neutralization or distortion of vowels
Suprasagmental deficits
Use more phonological processes than typically developing children
Initial and final consonant deletion
Cluster reduction
Voicing voiceless consonants
Children with sensorineural or mixed HI:
Language mediates cognition development
Language delay = cognitive delay
IQ normal but lower than normal hearing children
Language deficits may explain cognitive differences
Deaf culture and IQ
Norm-referenced tests
Sensorineural and mixed hearing losses
Normal language development, but often delayed
Syntax (inflectional morphemes)
Semantics (agent, action, object; relationship forms)
Discourse
Limited exposure to oral narratives
Pragmatic development (better than syntax, semantics)
Language Learning in Deaf Children
Children learn language through social interactions
Hearing parents may react differently to a child with a hearing loss
Can negatively influence language development
Parent-child interactions using ASL
Language
Literacy
Social and academic development
Literacy
Difficult for children with HI
Average reading comprehension for adolescent with HI is third-fourth grade
Study examining literacy skills of high school seniors with HI enrolled in mainstream or oral education programs (Geers & Moog, 1989)
Average to above average IQ
Good use of residual hearing
Strong oral English language skills
Syntax, semantics, discourse
Combined ASL and English instruction to improve literacy
Exposure to literacy & writing
Children with cochlear implants (CI)
Children implanted earlier tend to perform better
Implanted by preschool resulted in age-level language abilities (Schauwers, Gillis, and Govarts, 2005)
Intelligibility, syntax, and semantics improved with implantation
Early implantation and rehabilitation can improve intelligibility, discourse skills, and literacy (ASHA, 2004)
Children with CI out performed children with hearing aids (Geers, 2004)
Oral education was more effective than total communication
Children with Mild CHL
May be at risk for speech and language delay
Delays may not persist
Chronic otitis media (OM) but typical language development
Low risk for later language delay
History of OM and present with language delay
Educate and train families
Speech & Language Assessment
Use standardized and nonstandardized tests (to determine how they are functioning as compared to peers, and in individual strengths/weaknesses)
Speech and language production
Writing and reading
Discourse
Receptive language
Compare speech results to the audiogram (know what sounds they can hear before determining a problem)
Patterns of production and perception will inform treatment plans
Assessments results should be reported in terms of strengths and weaknesses
Treatment should build on strengths
Educational Approaches
Oral approach – English is used for speech, language, and literacy acquisition
Three variations
Auditory-oral: intensive speech instruction and auditory perception and speechreading are used to learn language
Auditory-verbal: auditory perception used to learn speech and language
Cued speech: auditory-oral approach is supplemented with hand cues
Total Communication
All communication modalities, but typically a combination of spoke English and invented sign
Invented sign forms of English- combine ASL signs and invented signs in ways that follow English word order rules
Manually coded English
Pidgin sign English
Bilingual/Bicultural approaches:
Knowledge and use of two languages and two cultures
ASL is considered the native language and English is the second language
Immersed in deaf and hearing culture
HL in Adults
Aural rehabilitation: focuses on improving effectiveness of communication for adults with hearing loss
Education:
Understanding hearing loss- both individual and family
Hearing aid and assistive devices selection and management
Legal Rights (right to continue working, right to education, rights not to face discrimination)
Training:
Strategies to improve auditory perception skills
Using visual cues
Individual and/or group treatment
