HI 1: Intro Flashcards
Describe normal hearing - range (dB, Hz).
Freq of everyday speech sounds?
20Hz-20KHz; 0-140dB
250-6000Hz
Range for Vowels, consonants. Impact of HL (mild, moderate)
Vowels - low Hz 250 to 1000Hz. Louder than consanants and low freq so least likely to be affected by HL.
Consonants (fshpkgshch) higher freq (and lower intensity) impacted first by HL.
UK degree of loss - BSA descriptors
0-20dB = Normal 20-40dB = Mild HL 40-70dB = Moderate HL 70-95dB = Severe HL 95-130dB = Profound HL 130+dB = Total HL
Conductive HL.
HL due to problem in outer/middle ear.
Results in a problem with transmitting sound to the inner ear.
Ossicles unable to vibrate properly => blockage or deformation within the middle ear. Common cause - middle ear infections or ruptured/damaged ear drums.
Temporary if treated (medically or surgery).
Untreated or persistent = permanent HL
Sensori-neural HL
HL due to problem in inner ear (cochlea to the vestibulocochlear nerve).
Caused - damaged/missing HC.
- HC @ apex damaged = low freq fucked
- HC @ base damaged = high freq fucked
HL permanent + irreversible
Issue w HL labels (e.g. mild) is that they’re reductionist. What other factors must you consider?
- Configuration of loss - what frequencies are impacted? How does this correlate to hearing speech sounds?
- Age at onset of loss - early onset can impact language acquisition.
- Amplification
- Speech perception abilities
CONFIGURATION OF HL
- Unilateral HL
- Bilateral HL
- Flat HL
- Low freq. loss
- High freq. loss
- Variable loss
Unilateral HL: Hearing is impaired in one ear.
Bilateral HL: Hearing loss occurs in both ears.
Flat HL: An even hearing loss across all frequencies.
Low freq. loss: A hearing loss is experienced below 2000Hz.
High freq. loss: A hearing loss is experienced above 2000Hz.
Variable loss: Hearing loss occurs at various frequencies.
AGE OF ONSET
Prelingual/congenital
○ Onset: HL present at birth
○ Causes: maternal infection, syndomes, prematurity, trauma, heredity, ototoxicity
○ Consequences: all aspects of spoken language (form, content, use)
AGE OF ONSET
Perilingual
○ Onset: After 5 years
○ Causes: infections (e.g. OME), disease (e.g. Meniere’s), trauma, noise, tumour, inherited deafness with delayed onset, ototoxicity (aminoglycosides)
○ Consequences: reception and intelligibility of speech, discourse
AGE OF ONSET
Postlingual/acquired
Onset is adulthood
When is a Hearing Loss Significant?
A hearing loss that is greater than 40dB (Fortnum et al., 2001)
In children “any degree of loss which affects language development” (Northern & Downs, 1991)
Adjustments to make when working w someone using an amplification device
- Always request an aided audiogram AS WELL AS an unaided audiogram.
- Always make sure that the amplification is working.
- Always ensure the acoustic environment is optimal - amplification devices work best in quiet environments.
Improving the listening environment for amp. users
Consider auditory factors - use a quiet room, soft furnishings, ensure that the amplification device is working.
Account for visual factors - use adequate lighting, and make sure there are no distractions.
Make sure seating provides clear access for speech reading, and position to allow for optimal signal to noise ratio.
2 models of deafness
The medical model considers hearing loss as an impairment, whereas the social model states that deaf people are linguistically and culturally different (Deaf vs. deaf).
Who are more likely to adopt a hearing identity? Deaf identity? Marginal??
Bat Chava (2000) states that a hearing identity is more likely to be adopted by deaf students in mainstream schools (this includes children with cochlear implants). Parental influences also contribute to the identity of the child.
Deaf identity is more likely to be adopted by children in deaf families, and by students in bilingual education contexts.
However, there is also a bicultural identity as well as a marginal identity. A marginal identity is more likely in children with hearing parents, or amongst hearing children with deaf parents (CODAs).
