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The purpose of this study was to investigate the relationship between live and recorded determinations of most comfortable loudness levels (MCL's) and to determine if a relationship existed between MCL's, tolerance levels (TL's), and acoustic reflex thresholds so that further research might be conducted regarding the use of acoustic impedance measures in hearing aid fitting.Thirty normal hearing female subjects were tested in this investigation. MCL's using live and recorded stimuli, TL's, and contralateral and ipsilateral acoustic reflex thresholds were obtained for each subject. Correlation coefficients were computed to determine if a relationship existed between any of the measurements.It was concluded that live voice stimuli yielded highly equivalent results to recorded stimuli in finding MCL's. Acoustic reflex thresholds were found to be poor predictors of MCL's and TL's. Before acoustic reflex measurements can be used in hearing aid fitting procedures, further research is warranted.

Custom-designed hearing instruments comprise the majority of those dispensed in the United States today. Because of their custom nature, there has been no means of evaluating them until they have been completed. There would be advantages to evaluating custom instruments prior to their completion. This study investigates a means of evaluating custom instruments prior to their final assembly into the customized shell. This is done by having the subject listen to the circuitry of the instrument while it is still mounted on the faceplate, which is accomplished by coupling the faceplate assembly to the subject's ear with foam earplug. To determine if the faceplate assembly, when coupled to the subject's ear, is a facsimile of the completed instrument, the insertion gain of the faceplate assembly was compared to the insertion gain of the completed instrument. Real ear measurements were obtained for both conditions (faceplate assembly vs. custom instrument) on twelve subjects. Once insertion gain was measured, the faceplate assemblies were then converted into custom instruments and insertion gain remeasured. A two-way Analysis of Variance test revealed no significant difference between the two test conditions at five representative test frequencies. A tolerance template, as specified by ANSI S3.22 1982, was used as a second criterion for similarity between two conditions. The tolerance template was superimposed over the insertion gain curves of the twelve faceplate assembly conditions to determine if the insertion gain curves of the completed instrument fell within acceptable variances. None of the insertion gain curves for the completed instruments fell completely within the tolerances allowed by the template. Based on this criterion, it was concluded there was a significant difference between the insertion gain of the two conditions and therefore the faceplate assembly was not a facsimile of the completed instrument, where insertion gain was concerned. However, from a subjective standpoint the faceplate assembly might still have some utility in the fitting of the custom in-the-ear hearing instruments. For example, it could be used to allow potential hearing aid wearers to experience different technologies during the preselection phase of the fitting process.

The purpose of this study was to compare the use of behind-the-ear and in-the-ear hearing aids with a geriatric population. The aids were compared to see which type of aid the subjects could learn to use most easily and to see which type of aid they preferred to use.Subjects were fitted with acoustically similar in-the-ear and behind-the-ear hearing aids for alternate one week periods. The aids were evaluated in two ways: 1) A rating scale evaluating the subjects’ abilities to use the hearing aid (insert battery, insert aid, remove aid, remove battery, adjust volume) and 2) A questionnaire exploring the subjects’ reaction to care of hearing aid use and general aid preference.With respect to the rating scale, no significant differences were found. Subjects could perform the tasks covered with both types of aids. With respect to the questionnaire, significant differences were found in favor of the in-the-ear hearing aid. In general, the results of this study tend to indicate that geriatric subjects can handle in-the-ear hearing aids and behind-the-ear hearing aids with about equal success but that they have a clear preference for in-the-ear hearing aids.

Uncomfortable listening level (UCL) is a behavioral measure which is currently used to set the maximum outputs of hearing aids. This study explored the feasibility of prescribing the maximum outputs of hearing aids by using results obtained from auditory brainstern response (ABR) testing. More specifically, this study compared ABR wave latencies with behaviorally-measured UCLs for a single cycle 3 kHz stimulus in normal-hearing adults.

Professional research project (Au.D.)--University of South Florida, 2000. / Title from PDF of title page. / Document formatted into pages; contains 46 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: In the present health care environment, there is an increased demand for audiologists to measure the outcomes of hearing aid intervention. In addition to the more traditional objective outcome measures, many subjective outcome measures have been developed in the last 20 years. Two such subjective outcome measures are the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Hearing Handicap Inventory for the Elderly (HHIE). These instruments consist of a series of pre-selected questions that may or may not be applicable to an individual. An alternative to the pre-selected question format is an open format design that allows the person with a hearing loss to designate areas of concern to them. One subjective outcome measure that uses this format is the Client Oriented Scale of Improvement (COSI) developed by Dillon and his colleagues in Australia. The COSI has been validated and may be useful for oversight with multi-clinician or for multi-clinic systems. The purpose of this study was to address tthe potential of the COSI for such oversight. Specifically, the study examined the inter-observer agreement of the classification of individually identified situations into general categories. The study also re-examined the clinical utility of the COSI as an outcome measure in individual hearing aid fittings. The results demonstrated very good inter-observer agreement for the classification of individually identified situations. In addition, the study supported the usefulness as a clinical outcome measure that had been found by Dillon and his colleagues in Australia. These results indicate that the COSI has potential for oversight of the outcomes of hearing aid intervention in hearing aid delivery organizations. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

The purpose of this study was to investigate the hypothesis that a dispensing program utilizing rehabilitative follow-up in the form of a post-fitting check appointment would show: (1) less return for repairs for hearing aids; (2) higher patient satisfaction with the aid; and (3) higher patient satisfaction with the service received during the hearing aid dispense than would a clinic with no follow-up. Data for comparison between the two clinics were drawn from medical chart review, frequency of hearing aid repairs, and from a questionnaire which assessed satisfaction levels. Patients were also asked to estimate the amount of use with the aid and success with manipulation of the aid for purposes of comparison with other groups previously studied.