Study Guide
1. Discuss the advantages of present day hearing aids relative to methods of amplification prior to 1960's.
2. Describe the physical aspects of hearing aid components (including microphone types, amplifiers,receivers, telecoils, power sources) and trace the signal pathway from microphone entrance to output of receiver.
3. Distinguish between various types of output limiting and note the relative advantages and disadvantages.
4.a. Discuss the various factors one must consider in designing an artificial ear and what data are available that one might use in doing so.
4.b. Describe the field-to-eardrum transfer function.
5. Recognize the acoustic cues which relate to various features of speech.
6. Distinguish between the three components of the. speech waveform and discuss how each one relates to amplification settings.
7. Contrast how information derived from the Al procedure differs from the information received from traditional speech recognition testing using PB word lists.
8. Descibe the most appropriate signal for soundfield testing of frequency specific thresholds by contrasting it with less appropriate signals.
9. Discuss the important factors to consider when calibrating soundfield and determining signal strength at the listener's ear.
10. Describe the electroacoustic measurements required by ANSI s3.22 and various rationales underlying the recommended procedures.
11. Describe how functional gain differs from 2cc coupler gain.
12. Describe the concepts of resistance, acoustic compliance, acoustic mass and resonance. Note where each effect may occur in the hearing aid coupling system.
13. Describe the relationship between resistance and reactance and frequency.
14. Contrast wavelength and helmholtz resonances; include how various manipulations of the coupling system affect these.
15. Relate possible modifications one could make in the coupling system if more high frequency emphasis was desired? more low frequency emphasis?
16. Contrast parallel and side-branch vents in terms of physical aspects, acoustic aspects, typical use situations.
17. Relate what acoustic modification to the coupling system may contribute to the possibility of feedback and those which reduce the possibility.
18. Given a case history deter-mine if a hearing aid evaluation is warranted.
19. Relate what factors would contra-indicate the use of ITE aid.
20. If you were a hearing manufacturer, determine what options all hearing aids in your line would possessand what options would be available on only some aids. Provide rationale for your decisions.
21. Discuss what information is necessary from an audiometric evaluation to determine hearing aid candidacy and why it is important.
22. Explain why UCL measurements under phones cannot be compared directly to 2 cc specs for selections MPO setting.
23. Explain why gain curves obtained with 2 cc coupler cannot be used as direct estimates of the gain the patient will realize with that hearing aid. Discuss how 2 cc specs can be translated to real ear gain and why you would want to do that.
24. Contrast various gain selection procedures in terms of basic premises, audiometric information needed, and validation.
25. Relate the problems with using PB 50 word lists to differentiate between aids during a hearing aid evaluation.
26. Given audiometric information determine whether compression is needed and what type. Describe desired settings for compression threshold, ratio, attach and release times.
27. How should the SSPL90 be set on a hearing aid of a child who cannot understand the concept of uncomfortable loud?
28. What types of aided information should be obtained during pediatric hearing aid evaluations?
29. What are the parent's responsibility with respect to amplification for their child?
30. Describe the "advocate" system for worldng with families of hearing-irnpaired children as reported by Stelrnachowicz et al.
3 I.What are two major problems encountered in carmold fitting for children?
32. Desciibe the effects on sound pressure in a closed auditory canal relative to that in an open one.
33. What is the rationale behind having stock ITC's?
34. When might the Janssen free field ITE be recommended?
35. What are advantages of and ITE over an ITC?
36. Describe test set up for electroacoustic measurements of FM system and for behavioral evaluation with FM system.
37. When might functional gain measures and insertion gain measures not agree?
38. Describe care and maintenance for hearing aids.
39. What suggestions might one give for initial amplification experience for adults and for children?
40. What tools are necessary to do an adequate listening check?
41. - Describe procedures for listening checks of: gain, SSPL:90, frequency response, compression circuitry
42. What are common causes of feedback, poor quality, dead hearing aid?
43."'What evidence might you use to convince public school administration to hire an audiologist?
44. What three measurements are essential with probe microphone system to determine insertion gain?
45. What are the advantages of probe mic measurements over behavioral measures?
46. Does the comparative hearing aid selection approach involve functional measurements whereas prescriptivehearing aid approach implies probe mic measures?
47. Explain how one could compare insertion gain to 2 cc coupler gain for a given individual and hearing aid.
48. What is the justification for fitting a CROS aid?
49. Describe the various CROS options and relate for whom they would be most,appropriate.
50. Describe how to evaluate a CROS fitting.
51. What are some of the arguments again fitting ITE's in children and what are the counter arguments to those?
52. What is proper insertion depth for probe microphone measures?
53. Why isn't it necessary to be in a free field to perform probe mic measures?
54. When can stimulus level be a problem in probe mic measures?
55. What are advantages and disadvantages of binaural amplification?
56. How should the merits of binaural amplification be evaluated?
57.For whom are vibrotactive aids appropriate and how do they benefit from such aids?
58. For whom are cochlear implants appropriate and how do they benefit from such?