The purpose of this study is to compare the Fonix Type 5000 Hearing Aid Test Set to the B&K system by testing the same hearing aids with both systems in order to determine whether there are any important differences between the measurements obtained using the two systems. Frequency response has been chosen as the measure on which the comparisons will be made.

published_or_final_version / Speech and Hearing Sciences / Master / Master of Science in Audiology

published_or_final_version / Education / Master / Master of Philosophy

Previous research has shown the benefit obtained by hard of hearing people when using inductive means (T-switch) to couple their hearing aids to telephone receivers. Benefit provided by receiver amplification in the telephone handset has also been shown. Informal surveys of hard of hearing people indicate that many of them use telephones having a dual capability: magnetic coupling and receiver amplification. The objective of this investigation was to study user performance with this dual capability. In particular, the effect of receiver amplification on the speech perception ability (as measured by R-SPIN test items) of 10 hard of hearing subjects using inductive means to couple their hearing aid to a telephone receiver was examined under both good and poor telephone line conditions. The influence of the predictability of the speech material presented was also investigated by noting any difference between the subjects' performance on high predictability items and performance on low predictability items (of the R-SPIN test). Results showed that the use of receiver amplification in conjunction with inductive coupling significantly improved the subjects' speech perception scores. Not surprisingly, good telephone line conditions also significantly improved the subjects' scores. Improvement due to receiver amplification was noted, irrespective of line conditions. Similarly, improvement due to good line conditions was observed, irrespective of whether amplification was used or not. Both receiver amplification and good line conditions had significant and positive effects on both low predictability and high predictability scores. We conclude that with speech either in or out of context, receiver amplification will be of benefit to those who use inductive coupling. Clinical implications and recommendations are discussed. / Medicine, Faculty of / Audiology and Speech Sciences, School of / Graduate

These two joint-studies used recorded versions of the Northwestern University Auditory Test Number 6 (NU-6) and the California Consonant Test (CCT) in the hearing aid evaluations (HAEs) of 12 male and one female subjects, aged 41 to 87 years. They exhibited precipitous high frequency losses beyond 1 kHz in at least one ear. All subjects were evaluated without amplification and while monaurally aided with two conventional high pass hearing aids. Ten of the subjects were evaluated in multi-talker noise and 11 were tested in quiet. Since the CCT was more heavily weighted than the NU-6 with target phonemes sensitive to high frequency losses, it was hypothesized that the CCT might be more sensitive than the NU-6 to significant differences between aided and/or unaided performances of these particularly high frequency impaired subjects. The data collected in noise and in quiet was analyzed separately with the one-way analysis of variance (ANOVA) for repeated measures. No significant differences were found in noise or quiet between the aided performances on either the CCT or the NU-6. The NU-6 in noise, however, revealed significant degrees of aided improvement at the .01 level of confidence that the CCT did not. The addition of noise seemed to make the CCT too difficult for these subjects. In quiet, both tests seemed to be as equally sensitive in revealing significant aided improvement at the .01 level of confidence. The lower mean CCT scores in quiet, however, seemed to indicate that if unaided NU-6 performances are too high to allow for significant aided improvement or significant differences between aids, the more time consuming CCT might be appropriate.

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This paper reports on the comparison of the performance of fourteen normal hearing listeners and fourteen individuals with sensorineural hearing loss on the Synthetic Sentence Identification (SSI) and the Northwestern Auditory Test No. 6 (NU 6) in order to determine whether there are differences in performance of the two groups of listeners on the SSI and NU 6 and whether either test better reflects aided improvement and residual deficit. Both measures demonstrated significant aided improvement. The results of this study do not suggest a single best discrimination test which can reflect a real-life listening situation. The primary consideration in the hearing aid evaluation is flexibility in determining the appropriate level for the primary signal and the listening conditions.

Hearing aid manufacturers commonly engineer automatic gain control (AGC) circuits which are aimed at reducing'sound tolerance problems and improving speech intelligibility among wearers. The most common type of AGC engineered is one utilizing a fast attack time. The present study was designed to evaluate the effects of both fast and slow attack times on the intelligibility of speech. Twenty-four normal hearing subjects listened to sixty pre-recorded sentences through two types of hearing aid circuits. Thirty sentences were modified by a fast attack AGC circuit, and thirty sentences were modified by a slow attack AGC. The subjects marked one of four multiple~choice answers for each sentence. The mean number of sentences answered incorrectly when heard through fast attack AGC was 8.25. When heard through slow attack AGC, the mean was 6.67. The performance differences which exist between these two modes of signal modification suggest that the fast attack does not improve intelligibility as significantly as slow attack time among normal listeners. Further investigation into the effects of slow attack AGC circuits on the user's ability to understand speech are recommended.

Professional research project (Au.D.)--University of South Florida, 2002. / Title from PDF of title page. / Document formatted into pages; contains 35 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The purpose of this study was to investigate the stability of hearing aid benefit, as measured by the Abbreviated Profile of Hearing Aid Benefit (APHAB; Cox & Alexander, 1995), between three months post hearing aid fitting and at next the annual audiological re-evaluation. The annual re-evaluation was at least, and as close to nine months as possible, after the previous audiological. The maximum time between the two evaluations was 18 months. Thirty-six hearing aid patients participated in this study. The participants were both male andfemale, and were fitted monaurally or binaurally with hearing aid(s). All participants had sensorineural hearing loss with no ongoing or permanent conductive or retrocochlear pathology. The APHAB scale was administered at the three month hearing aid check (HAC) and again at the annual audiometric re-evaluation. / Analysis of covariance (ANCOVA), with length of time between the three month hearing aid check (HAC) and the next audiological re-evaluation as a covariate, was used to examine the main effects of time of administration and subscale [e.g., ease of communication (EC), reverberant conditions (RV), background noise (BN), and aversiveness of sounds (AV) and their interactions. Results revealed a significant reduction in the mean benefit scores between the 3-month HAC and annual re-evaluation APHAB administration. It is hypothesized that the causal factor of the decrease in benefit in the EC, RV, & BN are multifactorial. / These reductions in benefits may be do to the Hawthorne effect, unrealistic hearing aid benefit expectations by the participants, or a heightened expectation of hearing aid benefit due to the financial expense. It should also be noted, however, that using the 90% confidence interval for "true" clinical benefit, 21 of the participants maintained stable benefit over the course of the study. Finally, although not statistically significant, the fourth APHAB scale, aversiveness of sounds (AV), improved over time. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Professional research project (Au.D.)--University of South Florida, 2002. / Title from PDF of title page. / Document formatted into pages; contains 45 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The aim of this study was to measure the effects of audiologic intervention on self-perceived quality of life in the elderly hearing-impaired population. The tested hypothesis was that hearing aid use would result in improved quality of life as measured by utilities. In this study, utilities were obtained using the U-Titer II, an interactive software program designed to measure an individual's health state preference or utility. This study also examined the issue of numeracy, which is described as an understanding of basic probability, and its effect with an individual's ability to accurately complete utilities. / Data from 54 individuals fit with hearing aids in this randomized, controlled, pre-test/post-test experimental design study were analyzed. The participants completed the U-Titer II, a test of numeracy and the International Outcome Inventory for hearing Aids (IOI-HA). Three utility approaches were used in this study: Time Trade-Off (TTO), Standard Gamble (SG) and Rating Scale (RS). With each of the utility approaches, disease-specific (e.g., deafness vs. perfect hearing) and generic (death vs. perfect health) anchors were incorporated. / Several research questions were posed to examine the sensitivity of utilities to hearing aid intervention. Question 1: Can the effects of hearing aid intervention be determined with a utility approach? Statistically significant differences between pre- and post-intervention utility scores were measured with disease-specific and generic anchors for only the TTO and RS approaches. These findings suggest that hearing aid intervention outcomes can be measured using either the TTO or RS utility approaches. / Question 2: Is numeracy ability a factor in the usefulness of a utility approach for assessing the effects of hearing aid intervention? Statistical analysis showed that mean utility scores changed very little as a function of numeracy ability. These findings suggest that numeracy ability does not appear to affect utility scores. Question 3: What, if any, are the relationships between hearing aid benefit as measured by a utility approach and hearing aid benefit as measured by the IOI-HA? / Spearman Rho correlations were conducted on the benefit data obtained from the two self-report measures (IOI-HA and utilities). The major findings from these analyses determined that the IOI-HA total scores were significantly correlated with utility outcomes as measured by TTO generic, TTO disease-specific, and RS disease-specific anchors. In general, correlations between the measures were higher with the disease-specific anchors than the generic anchors. Also, none of the correlations between any IOI-HA outcome domains and utility change scores with generic anchors obtained with the RS scale were significant. / For utilities measured with disease-specific anchors, significant correlations were found with two IOI-HA outcome domains (benefit and satisfaction) and utility change scores as measured by the TTO technique. When the RS technique was utilized, significant correlations were found for four of the seven outcome domains (benefit, satisfaction, participation and impact of others). Thus, if the IOI-HA is used as a measure against which to validate the utility approach as a measure of hearing aid outcomes, the measure with the most face validity is a RS method with disease-specific anchors. However, if one wished to compare hearing aid intervention to intervention in other areas of health care, these data support the use of a TTO approach. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.