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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.

The long-term outcomes of subjects fitted with a bone anchored hearing aid (BAHA) for a unilateral profound sensorineural hearing loss (UPSHL) are still evolving. Previous studies have focused on the comparison between shortterm outcomes obtained with hard-wired contralateral routing of signal (CROS) hearing aids and those obtained with BAHA devices. Published results on subjects who have worn their BAHA devices for UPSHL for more than twelve months are limited. This study explored the long-term outcomes of adults fitted with a BAHA for UPSHL. The aims were firstly to examine subjects' pre-operative and postoperative speech perception in quiet and noise, as well as administer two standardised questionnaires, the Abbreviated Profile of Hearing Benefit (APHAB) and the Glasgow Hearing Aid Benefit Profile (GHABP). The second aim was to evaluate the responses of implanted subjects following the preoperative test protocols using a supplementary questionnaire, the Single Sided Deafness Questionnaire (SSDQ). The third aim was to monitor the subjects' implant or repair issues. In addition, questionnaire results were compared to subjects who underwent pre-operative assessment but were not implanted. All subjects had a UPSHL resulting from various aetiologies including vestibular schwannoma or other skull base tumour removal, viral infections, cochlear trauma, idiopathic sudden hearing loss, and Meniere's disease. There was a significant difference between the implanted groups' pre- and post-operative outcomes measures, indicating a treatment effect from the fitting of the BAHA device. No significant changes were found with the non-implanted groups' longterm outcome measures in regards to their perceived hearing difficulties. No significant correlations were found between outcome measures and gender, age of fitting, length of deafness, or ear affected for either group.

Bone conduction transmission and head‐shadow effects were determined with transcranial completely‐in‐the‐canal (TCCIC) CROS hearing aids. Five subjects with documented profound unilateral hearing loss and experience with traditional CROS/BICROS fittings (TCROS) were tested with a CIC hearing aid placed in their poorer ear. Peak SPL was measured at the tympanic membrane and ranged from 105–115 dB SPL at 2000 Hz. Pure‐tone crossover thresholds and functional gain tested at frequencies from 250–8000 Hz varied considerably more than the SPL measures. The pure‐tone results indicated that sensitivity in the better ear was moderately associated with functional gain across frequency. Speech recognition was then tested in the sound field in two conditions: direct (noise in the poorer ear, speech in the better ear) and indirect (noise in the better ear, speech in the poorer ear) at S/Ns of −6, 0, +6, +12, and quiet. The TCCIC fittings were more effective than TCROS aids across S/Ns, particularly in the direct condition. In the indirect condition, the two fittings performed similarly. When data were pooled across conditions, the TCCIC aids provided better word recognition than the TCROS aids, particularly for those subjects with greater sensitivity in the better ear.

The objective of the dissertation research is to investigate noise reduction methods for binaural hearing aids based on array and statistical signal processing and inspired by a human auditory model. In digital hearing aids, wide dynamic range compression (WDRC) is the most successful technique to deal with monaural hearing losses. This WDRC processing is usually performed after a monaural noise reduction algorithm. When hearing losses are present in both ears, i.e., a binaural hearing loss, independent monaural hearing aids have been shown not to be comfortable for most users, preferring a processing that involves synchronization between both hearing devices. In addition, psycho-acoustical studies have identified that under hostile environments, e.g., babble noise at very low SNR conditions, users prefer to use linear amplification rather than WDRC. In this sense, the noise reduction algorithm becomes an important component of a digital hearing aid to provide improvement in speech intelligibility and user comfort. Including a wireless link between both hearing aids offers new ways to implement more efficient methods to reduce the background noise and coordinate processing for the two ears. This approach, called binaural hearing aid, has been recently introduced in some commercial products but using very simple processing strategies. This research analyzes the existing binaural noise-reduction techniques, proposes novel perceptually-inspired methods based on blind source separation (BSS) and multichannel Wiener filter (MWF), and identifies different strategies for the real-time implementation of these methods. The proposed methods perform efficient spatial filtering, improve SNR and speech intelligibility, minimize block processing artifacts, and can be implemented in low-power architectures.

Thesis (Au.D.)--James Madison University, 2010. / Includes bibliographical references.

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Call number: LD2668 .T4 1985 S99 / Master of Arts

Thesis (MPhil)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: Technology and disability are both terms laden with associations, values, meanings and even myths. This becomes clear in this research when both terms are described in the first part, and the various understandings of the terms are explained. When the two terms are considered in relation to each other, the result is a series of questions and ethical problems. In this assignment the focus is specifically on these questions and ethical problems that arise out of the relationship between technology and disability. The research is not done from a natural science perspective (with regard to technology) and lor a medical perspective (with regards to disability), but from a philosophical-ethical perspective. The main aim of this research is to think about what the role of technology is in the life of the disabled in general and what ethical questions arise from it. To form a philosophical-ethical perspective the question is asked: should technology be accepted unequivocally as something that always contributes to the humanization of the disabled? More specifically the assignment focuses on the issue: does cochlear implants contribute to the humanization of the deaf? The potential problematic relationship between the concepts is clear from the separate discussions. The limitations and problems of cochlear implants as an example of technology is shown when it is placed within the framework of a humanizing relationship. It is clear that technology can not be accepted unequivocally as something that always contributes to the humanization of the disabled. The research emphasizes that disability is much more than physical limitations and that compensating for the limitations through technology does not always address all the aspects of a disabled person's life - and can consequently have a dehumanizing effect. A more holistic approach is considered - one in which all the aspects of being human is addressed. The unique challenges of the South African context is discussed shortly and in conclusion the necessity of an "ethics of responsibility" is shown. Reflection on technology and disability is in the end reflection on life and the mysteries of life. Disability that reminds us of our limitations and shortcomings, also reminds us that life is not in our control and that a big part of living is an unsolvable riddle, a mystery. / AFRIKAANSE OPSOMMING: Tegnologie en gestremdheid is twee gelade terme. Beide verwys na 'n omvangryke wêreld en potensiële probleme. Dit word duidelik in hierdie ondersoek wanneer beide terme omskryf word in die eerste afdeling, en die verskillende verstaansmoontlikhede van die terme uitgewys word. Waar die twee terme in verband met mekaar gebring word, ontstaan daar uiteindelik 'n hele string vrae en etiese probleme. In hierdie skripsie word daar spesifiek op hierdie vrae en etiese probleme, wat ontstaan uit die verhouding tussen tegnologie en gestremdheid, gefokus. Die ondersoek vind nie plaas vanuit 'n suiwer natuurwetenskaplike perspektief (mbt tegnologie) en/of mediese perspektief (mbt gestremdheid) nie, maar vanuit 'n filosofies-etiese perspektief. Om 'n filosofies-etiese perspektief te vorm, word die vraag gevra: moet tegnologie ongekwalifiseerd aanvaar word as iets wat altyd bydra tot die humanisering van die gestremdes? Meer spesifiek word dan ondersoek ingestel na die vraag: dra kogleêre inplantings by tot die humanisering van die dowe? Die vernaamste doel met hierdie ondersoek is dus om na te dink oor wat die rol van tegnologie in die lewe van gestremdes in die algemeen is en watter etiese kwessies dit oproep. Die problematiek rondom dowes en kogleêre inplantings gaan as 'n spesifieke voorbeeld bekyk word. Die begrippe tegnologie en gestremdheid word eers omskryf in die ondersoek. Die potensiële problematiek tussen die verhouding tussen die twee terme (en wêrelde) blyk reeds uit die afsonderlike bespreking van die terme. Die verhouding waarin tegnologie en gestremdheid tot mekaar staan word uitgelig deur sekere voorbeelde te noem, en dan word daar spesifiek op kogleêre inplantings gefokus. Die beperkings en problematiek van kogleêre inplantings as spesifieke tegnologie word duidelik wanneer dit binne die raamwerk van die vraag gestel word of dit 'n humaniserende verhouding is. Dit is duidelik dat tegnologie nie ongekwalifiseerd aanvaar kan word as iets wat altyd bydra tot die humanisering van die gestremdes nie. Die ondersoek beklemtoon uiteindelik dat gestremdheid veel meer behels as blote liggaamlike gebreke en dat die kompensasie daarvoor deur tegnologie nie altyd as humaniserend ervaar word nie. 'n Meer holistiese benadering word bepleit - een waarin alle fasette van die mens (gestremde) se behoeftes aangespreek word. Die unieke uitdagings wat dit inhou vir ons Suid-Afrikaanse konteks word kortliks bespreek en ten slotte word daar gewys op die noodsaaklikheid van 'n letiek van verantwoordelikheid'. Nadenke oor tegnologie en gestremdheid is uiteindelik nadenke oor die lewe en oor die geheimenisse daarvan. Gestremdheid wat ons herinner aan ons tekortkominge en beperkinge, herinner ons ook daaraan dat die lewe 'n misterie is.