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Maximizing Speech Intelligibility for Open Canal Fittings

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1.  According to the authors, what is one reason why open fit hearing aids often require additional fine tuning adjustments from the initial settings: Open fittings present a high risk for feedback so only a small frequency region is effectively amplified and this is not accounted for in many fitting strategies Current fitting strategies do not take into account the unique acoustical parameters such as various dome and tubing sizes The occlusion effect may be prevalent even in open fittings All of the above

2.  The authors discuss evidence suggesting that in downward sloping hearing losses, it may not be advisable to provide amplification to frequencies where hearing thresholds: are in the mild hearing loss range are measured with headphones rather than insert earphones are in the moderately-severe hearing loss range or greater None of the above

3.  Which of the following statements is TRUE: The contribution of audibility to speech intelligibility is the same for normal hearing listeners and listeners with hearing loss, regardless of degree. The contribution of audibility to speech intelligibility is the same at 2000 Hz and 4000 Hz for all listeners. Some evidence suggests that increased audibility in the high frequencies can negatively impact speech perception for people with severe hearing loss in that range. Speech intelligibility improves linearly with increasing audibility for people with profound hearing loss at 4000 Hz at the same rate as those with thresholds of 60 dB at that frequency.

4.  Another term for maximum feedback-free gain is: Maximum stable gain Critical gain Dynamic gain Both A & B

5.  The stationary component of the feedback path: Can be defined as the component that depends on the use of the hearing aid in everyday life - such as with chewing and jaw movements, head movements, etc. Can be measured by conducting an open loop gain measurement Does not depend on the impedance characteristics of the individual ear canal, or location of the hearing aid microphone Will not vary from individual to individual

6.  Results of an Open Loop Gain (OLG) measurement: Indicate the maximum stable gain that can be potentially delivered before feedback Represent the attenuation of a signal from the ear canal to the hearing aid microphone Depends on ear acoustics, tubing, domes, and microphone location All of the above

7.  Which of the following is FALSE in regard to the OPEN algorithm: OPEN calculates initial targets based on DSL i/o v. 5 OPEN adjusts initial target gain based on an individual OLG measurement or a statistical critical gain curve OPEN may use loudness perception and psychoacoustic models to optimize speech intelligibility OPEN has been evaluated in several studies

8.  A study of the OPEN algorithm at the University of Munich reached which of the following conclusions: OPEN provided greater speech intelligibility in quiet than NAL-NL1 for all subjects in all conditions OPEN did not reduce speech intelligibility in quiet as compared to NAL-NL1 even when less gain was prescribed OPEN always prescribed more overall gain than NAL-NL1 None of the above

9.  A study of instruments fit with the OPEN algorithm at Horzentrum Oldenburg reached which of the following conclusions: Participants indicated feedback was rarely a problem Sound quality was rated very high Speech intelligibility was rated very high All of the above

10.  The OPEN algorithm is recommended for: Wearers with high frequency hearing losses utilizing open canal fittings Wearers with flat profound hearing loss wearing superpower BTE instruments Wearers with custom hearing instruments and reverse slope audiograms Wearers of all hearing loss configurations utilizing receiver-in-canal instruments, regardless of whether the fitting is open or closed