Special Cases and Hearing Aid Programming Alternatives Flashcards

Question

What are the 3 types of NIHL?

Answer 1

Type 1 - few years of exposure, normal or near normal 2kHz, special fittings aren't necessary Type 2 - many years of excessive exposure, threshold loss extends to LF (below 2000 Hz), use of typical fitting strategies may be helpful if the output supplies HF audibility Type 3 - extreme cases, hearing is near normal for LF only, thresholds shows a precipitous slope, special fitting strategies needed

Answer 2

Outer hair cell (OHC) damage in the cochlea leads to abnormal loudness growth (recruitment) Potential distortion for patients with damaged or absent inner hair cells (IHC) - Dead regions High frequency output is limited by feedback WRS test may not accurately reflect patients ability (cannot make signals loud enough for effective testing) Full HF audibility is not a reasonable goal due to comfort and sound quality

Answer 3

Assume the presence of dead regions for thresholds >70 dB HL Assume the presence of dead region for precipitous slopes >20 dB/ octave Would not perform TEN test Avoid adding gain to any frequency meeting these criteria

Answer 4

Evidence finds dead regions are present in only 1/3 of individuals with hearing loss Dead regions may be present at levels as low as 55 dB HL Prevalence increases with only a 10 dB slope in 2-4KHZ region Most individuals only have 1-2 dead regions frequencies (only 3% of patients with dead regions have extensive dead regions) - more than 3 regions TEN test not necessary for all patients

Answer 5

Maybe Do not assume this individual needs reduced high frequency output Patients appear to benefit from HF gain if only 1-2 dead region frequencies between 1-4k Hz are present 2/3 of patients with “extensive dead regions” (> 3 DR’s) PREFERRED high frequency audibility (pull away HF output if the patient is not liking the sound)

Answer 6

Focus on supplying gain to heathier areas of the cochlea in the low and mid-frequencies There’s no need to select a receiver offering wider frequency responses with extended high frequencies

Answer 7

Add gain to thresholds below 85 dB HL Strive to achieve a balance audibility from 500 Hz up to 3k Hz for thresholds below 85 dB HL Add 5-8 dB of gain to normal thresholds just before the precipitous drop (benefits sound quality) Enable expansion to reduce mic noise when hearing is near normal below 2k Hz If a threshold is near LDL, apply no gain or 1/5 the threshold (20% of threshold vs. 46%)

Answer 8

Automatic directional mics enhance intelligibility (minor improvements to SNR can increase intelligibility) Avoid too many compression ratios (reduces spectral contrasts between vowels and consonants - smooth increase rather than abrupt) Select brands using true phase cancellation DFS (preserves HF output by adding as much as 10 dB of gain) Increase ear canal length to increase output and decrease occlusion effect

Answer 9

4-6 weeks after initial fit Understand the brands signal processing algorithm before enabling it Verify FL output to ensure speech information moves to audible region w/o unduly limiting bandwidth of the entire signal Validate effectiveness with objective measures & self report questionnaires

Answer 10

Phonak, Unitron, Signia

Answer 11

Starkey, Oticon, Bernafon

Answer 12

Steeply sloping loss Severe to profound loss

Answer 13

Fine-tune to the weakest possible setting for improved audibility

Answer 14

Improve detection of high frequency speech sounds Improve discrimination of S from SH, particularly after a period of acclimatization Increase activity in auditory cortex for high frequency stimuli Settings stronger than this are associated with diminished sound quality

Answer 15

Used when programming FL (FL turned off during this test) Maps the region where audibility ends Lower limit- the frequency where the LTASS becomes inaudible Upper limit- the upper range frequency where the speech envelope becomes inaudible

Answer 16

Disable digital noise reduction Signal: calibrated /S/ presented at 65 dB SPL Verify audibility: when the upper shoulder of the MOAF is audible with a DISABLED Frequency lowering Enable Frequency lowering to verify if audibility of a calibrated /s/ input signal is achievable Adjust until the upper shoulder is audible by about 10 dB Ideally, an “SH” signal is 100 Hz lower than the “S” (used as a check)

Answer 17

Yes It copies the original HF signal and transposes it to the lower frequencies Observe both humps on graph

Answer 18

Audibility within residual hearing regions (healthier regions of the cochlea)

Answer 19

The addition of too much gain in low frequencies leads to upward spread of masking Satisfaction may be limited due to increased likelihood of extensive dead regions (>3 DR) (no frequency raising)

Answer 20

Add only 15-20 dB of gain in low and mid frequencies initially Add 10-15 dB at 2k Hz & above of gain for increased audibility (even at normal thresholds) Allow time for habituation before further increase (some may want more LF gain and some may need less) Add gain to the MF and be cautious when adding LF gain Modify HF gain based on individual perceptions

Answer 21

Yes Air/bone gaps attenuate the signal’s amplitude before it arrives to the cochlea

Answer 22

No Compression is not needed because the dynamic range is normal Use of 1:1 linear signal processing (or very low CR) is fine

Answer 23

Yes Compression is needed in addition extra gain due to the reduced dynamic range

Answer 24

Calculate prescriptive gain recommendation for AC threshold Calculate 25% of A-B gap. This additional gain is added to the AC prescriptive targets Increase MPO by the same percentage used for A-B gap calculation allowing headroom for the extra gain

Answer 25

Yes Provides this calculation when the BC thresholds are entered into the verification unit DSL 5.0 does not compensate for additional gain needs

Answer 26

Maybe yes, but maybe no! Each brand you use must be evaluated to identify potential limitations

Answer 27

Minimal hearing loss

Answer 28

25-35 dB CHL

Answer 29

About 40 dB CHL

Answer 30

Could be a loss as great as 60 dB

Answer 31

Bone conduction/bone anchored devices Ear level devices (might vary recommendations based on if it's a dry perf or wet perf; might need airflow)

Answer 32

No, you need to consider how they obtained their loss They are all different and should be treated that way Residual hearing in this population varies significantly from patient to patient There may be mechanical and metabolic disruptions, membrane disruptions, large sections of inner hair cell loss, neural cell death, etc.

Answer 33

Yes Reduced reliance on audibility This population relies on alternative communication strategies which are supplemented by amplification Amplification may be needed to support speech reading skills or for environmental sound awareness May prefer a linear signal and prefer a signal processing of one brand

Answer 34

Yes Some individuals may not be able to extract information from a compressed signal, others need less compression to decode the incoming signal Don’t rely on a targeted approach; begin with very low CR’s & listen to your patient instead If they complain that speech is ‘muddled’, or indistinct modifications are needed, change to slow acting compression to maintain a longer non-compressed state (maintain a more linear aspect of the speech signal, reduce CR, audibility of the signal only above the LTASS may be preferred)

Answer 35

Use a prescriptive formula designed for this population (NAL-RP) Begin by establishing their upper-level limits (LDL) (reset MPO to LDL in fitting software to maximize available headroom) Evaluate audibility at 65 dB SPL It’s okay if signal audibility below LTASS may not be possible Verifying a 55 dB signal isn’t necessary Use objective assessments to evaluate patient’s ability to extract speech cues Sentences in quiet; sentences in noise vs. noise; sentence with speech reading