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

Being given the diagnosis of a disability generally affects an individual's emotional state, however, this has not previously been investigated with respect to audiology and the diagnosis of hearing loss. The first aim of this study was to describe some of the common initial reactions to the diagnosis of hearing loss (HL). An awareness of these emotional reactions will aid audiologists in counselling their patients. Counselling occurs at the time of the diagnosis and throughout the aural rehabilitation process. However, counselling tuition is currently not provided for audiology students at New Zealand universities and there are few professional development courses for practicing audiologists. The second aim of this study was to evaluate current audiological counselling services and ascertain the impact on patients' decisions to get hearing aids (HAs). To accomplish these aims, 27 adults who had been newly-diagnosed with a HL completed an initial reaction questionnaire, partook in an interview which followed up on the questionnaire, and subsequently completed a second questionnaire at least three weeks later. There were two versions of the second questionnaire, depending on whether they had chosen to have HA(s) fitted. The results found that the common emotions reported were a sense of loss, sadness and resignation, as well as relief. Furthermore, an individual's level of optimism tended to decrease in response to the hearing test result. The ratings of the audiological counselling services were positive and seemed not to significantly influence the individual with respect to their decision to purchase HAs. The two areas of audiological counselling which could be improved related to how the audiologist explained the HL, particularly in relation to the individual's life, and also the provision of information to patients prior to the fitting of the HA. In addition to the data that was collected in relation to these aims, information was collected with respect to patients' perceptions of their HL prior to the hearing test, their interpretation of the hearing test results, and also how the patient's significant other responded to the diagnosis. The information from this study will be useful for equipping audiologists, both new graduates and those with more experience, to provide optimal audiological care for their patients.

A clinically-focused music appreciation training program (MATP) was developed for use by recipients of cochlear implants (CI) and wearers of hearing aids (HA). It aimed to enhance listeners’ music appreciation abilities, with a specific focus on timbre and musical style. The MATP was pilot-tested on 17 adult postlingually deafened CI recipients (8 female, 9 male, mean age = 60.2 years) and 13 adult HA users (7 female, 4 male, mean age = 63.9 years), with each device group divided into a control and a training group. The training groups were asked to use the MATP for 30 minutes per day four times a week for 10 weeks. The control groups were asked to continue with their normal listening habits for the same time period. Both the training and control groups were assessed on tests of instrument, ensemble and style identification as well as pleasantness ratings of musical excerpts, before and after the 10-week period. Participants in the training groups also completed a program evaluation questionnaire at the end of the training period. The results showed that the training program significantly improved the quality ratings of CI recipients for ensemble stimuli (p = .034). There were, however, no significant improvements for CI users on the timbre discrimination tasks or quality ratings for single instruments, nor were there any significant improvements for the HA users on any of the discrimination tasks or in their quality ratings. The findings suggest that CI recipients’ quality appraisal can be improved through training, independent of perceptual accuracy. On evaluating the program, the majority of CI and HA trainees reported that the MATP was enjoyable and beneficial in terms of music appreciation. Future directions for continued development of the MATP and testing of its efficacy are discussed.

Research has shown that re-learning to understand speech in noise can be a difficult task for adults with hearing aids (HA). If HA users want to improve their speech understanding ability, specific training may be needed. Auditory training is one type of intervention that may enhance listening abilities for adult HA users. The purpose of this study was to examine the behavioral effects of an auditory training program called Listening and Communication Enhancement (LACE™) in the Digital Video Display (DVD) format in new and experienced HA users. No research to date has been conducted on the efficacy of this training program. An experimental, repeated measures group design was used. Twenty–six adults with hearing loss participated in this experiment and were assigned to one of three groups: New HA + training, Experienced HA + training or New HA – control. Participants in the training groups completed twenty, 30 minute training lessons from the LACE™ DVD program at home over a period of 4-weeks. Trained group participants were evaluated at baseline, after 2-weeks of training and again after 4- weeks of training. Participants in the control group were evaluated at baseline and after 4-weeks of HA use. Findings indicate that both new and experienced users improved their understanding of speech in noise after training and perception of communication function. Effect size calculations suggested that a larger training effect was observed for new HA users compared to experienced HA users. New HA users also reported greater benefit from training compared to experienced users. Auditory training with the LACE ™ DVD format should be encouraged, particularly among new HA users to improve understanding speech in noise.

The present thesis examined the extent to which background noise influences the isolation point (IP, the shortest time from the onset of speech stimulus required for correct identification of that speech stimulus) and accuracy in identification of different types of speech stimuli (consonants, words, and final words in high-predictable [HP] and low-predictable [LP] sentences). These speech stimuli were presented in different modalities of presentation (auditory, visual, and audiovisual) to young normal-hearing listeners (Papers 1, 2, and 5). In addition, the present thesis studied under what conditions cognitive resources were explicitly demanded in identification of different types of speech stimuli (Papers 1 and 2). Further, elderly hearing-aid (EHA) users and elderly normal-hearing (ENH) listeners were compared with regard to the IPs, accuracy, and under what conditions explicit cognitive resources were demanded in identification of auditory speech stimuli in silence (Paper 3). The results showed that background noise resulted in later IPs and reduced the accuracy for the identification of different types of speech stimuli in both modalities of speech presentation. Explicit cognitive resources were demanded in identification of speech stimuli in the auditory-only modality, under the noisy condition, and in the absence of a prior semantic context. In addition, audiovisual presentation of speech stimuli resulted in earlier IPs and more accurate identification of speech stimuli than auditory presentation. Furthermore, a pre-exposure to audiovisual speech stimuli resulted in better auditory speech-in-noise identification than an exposure to auditory-only speech stimuli (Papers 2 and 4). When comparing EHA users and ENH individuals, the EHA users showed inferior performance in the identification of consonants, words, and final words in LP sentences (in terms of IP). In terms of accuracy, the EHA users demonstrated inferior performance only in the identification of consonants and words. Only the identification of consonants and words demanded explicit cognitive resources in the EHA users. Theoretical predictions and clinical implications were discussed. / I denna avhandling undersöktes hur mycket bakgrundsbuller inverkar på isolationspunkten (IP, den tidigaste tidpunkt när ett talat stimulus kan identifieras korrekt) och exakthet i identifikation av olika typer av talade stimuli (konsonanter, ord, och ord i final position i högt predicerbara [HP] respektive lågt predicerbara [LP] meningar). Dessa talade stimuli presenterades i olika modaliteteter (auditivt, visuellt, och audiovisuellt) för unga normalhörande deltagare (Artikel 1, 2 och 5). Dessutom jämfördes under vilka betingelser explicita kognitiva resurser krävdes för identifikation av olika typer av talade stimuli (Artikel 1 och 2). Vidare jämfördes äldre hörapparatsanvändare (EHA) och äldre normalhörande (ENH) personer med avseende på IP, exakthet i identifikation, och under vilka betingelser explicita kognitiva resurser krävdes för auditiv identifikation i tystnad (d.v.s. utan bakgrundsbuller) (Artikel 3). Resultaten visade att bakgrundsbuller gav senare IP och sänkte exaktheten för identifikation av olika typer av talade stimuli och i båda modaliteterna för presentation. Explicita kognitiva resurser krävdes vid identifikation av talade stimuli vid rent auditiv presentation med bakgrundsbuller, och när ingen semantisk förhandsinformation presenterades. Dessutom resulterade audiovisuell presentation i tidigare IP och mer exakt identifikation av talade stimuli, jämfört med rent auditiv presentation. Ett ytterligare resultat var att förexponering av audiovisuella talade stimuli resulterade i bättre identifikation av tal i bakgrundsbrus, jämfört med förexponering av enbart auditiva talade stimuli (Artikel 2 och 4). Vid jämförelse av EHA-användare och ENH-personer, hade EHA-användare senare IP i identifikation av konsonanter, ord, och ord i final position i LP-meningar. Dessutom hade EHA-användare mindre exakt identifikation av konsonanter och ord. Endast identifikation av konsonanter och ord krävde explicita kognitiva resurser hos EHA-användare. Teoretiska prediktioner och kliniska implikationer diskuterades.

In the future, audiological rehabilitation of adults with hearing loss will be more available, personalized and thorough due to the possibilities offered by the internet. By using the internet as a platform it is also possible to perform the process of rehabilitation in a cost-effective way. With tailored online rehabilitation programs containing topics such as communication strategies, hearing tactics and how to handle hearing aids it might be possible to foster behavioral changes that will positively affect hearing aid users. Four studies were carried out in this thesis. The first study investigated internet usage among adults with hearing loss. In the second study the administration format, online vs. paper- and pencil, of four standardized questionnaires was evaluated. Finally two randomized controlled trials were performed evaluating the efficacy of online rehabilitation programs including professional guidance by an audiologist. The programs lasted over five weeks and were designed for experienced adult hearing-aid users. The effects of the online programs were compared with the effects of a control group. It can be concluded that the use of computers and the internet overall is at least at the same level for people with hearing loss as for the general age-matched population in Sweden. Furthermore, for three of the four included questionnaires, the participants’ scores remained the same across formats. It is however recommended that the administration format remain consistent across assessment points. Finally, results from the two concluding intervention studies provide preliminary evidence that the internet can be used to deliver education and rehabilitation to experienced hearing aid users who report residual hearing problems and that their problems are reduced by the intervention; however the content and design of the online rehabilitation program requires further investigation.

Infants with hearing loss (HL) are being diagnosed and fitted with amplification earlier than ever before. In order to acquire speech and language abilities that are on par with their normal-hearing (NH) peers, hearing-impaired (HI) infants require amplification that provides appropriate exposure to the sounds of their native language. To date, no research has addressed this issue and thus, there is a need to examine the type of amplification that is most suitable for infants during the early stages of language acquisition. In this thesis, three different amplification types were compared: one that preserves the natural spectral shape of speech (unmodified speech); a second that emphasises high-frequency speech information (positive spectral tilt); and a third that emphasises low-frequency information (negative spectral tilt). NH infants were tested to examine how each of these amplification types affects speech perception and to explore whether infants at different stages of language acquisition find modified spectral tilt a help or hindrance in perceiving native-language speech contrasts. A visual habituation (VH) procedure was used to test 288 6- and 9-month-old NH infants on their ability to discriminate the high-frequency fricative contrast /f/- /s/; the mid-frequency approximant contrast /l/-/r/; and the low-frequency vowel contrast /5/-/N/ under modified spectral tilt conditions. For each speech contrast, 96 infants were tested in one of three conditions: (a) unmodified spectral tilt (n = 32); (b) with a positive 6 dB/octave spectral tilt (n = 32); or (c) with a negative 6 dB/octave spectral tilt (n = 32). The results showed that both 6- and 9-month-olds discriminated the three speech contrasts in the unmodified condition. However, when the contrasts were spectrally modified, a consistent developmental trend emerged. Six-month-olds’ discrimination performance improved when the spectral tilt modification amplified the relevant frequency information. That is, for the consonant contrasts (fricatives /f/-/s/ and approximants /l/-/r/) 6-month-olds performed best when high-frequency information was emphasised, whereas for the vowel contrast (/5/-/N/) the best discrimination performance was found when low-frequency information was enhanced. Nine-month-olds, on the other hand, showed no evidence of discriminating any of the contrasts when spectral tilt was modified. For all three contrasts, the older infants’ best discrimination performance was in the unmodified spectral tilt condition. The findings reflect the early stages of linguistic development. Six-month olds, whose acoustically driven speech perception operates in a language-general mode, demonstrated a broad-based ability to discriminate speech sounds. They not only accommodated speech with positive or negative spectral tilt, but a facilitation effect was observed when relevant frequency information was amplified. In contrast, 9-month-olds, whose perception is linguistically driven, found that spectral tilt modifications hinder speech perception. It seems that because older infants are attuning to native phonemic categories, their attention is constrained to native language spectral profiles only. Thus, even those spectral tilt modifications that should have been beneficial for perception were eschewed by 9-month-olds because they were incompatible with the older infants���� narrow focus on spectrally intact native speech sounds. Only NH infants were tested in this study, so it is not possible draw firm conclusions about amplification schemes until HI infants are tested too. Nevertheless, the results have a number of implications for infants with HL. The demonstration that spectral tilt modifications interfere with older NH infants’ speech perception suggests that future research should investigate whether HI infants also show this developmental pattern. That is, do HI infants progressively attune to the native language, and if so, does this affect their perception of spectrally modified speech sounds? Moreover, if HI infants are to attune to the native language and acquire speech and language in the same way as their NH peers, then the research reported here suggests that, throughout infancy, HI infants will need access to amplified speech that maintains the spectral shape of natural speech. Thus, the current research demonstrates, for the first time, a developmental difference in the way that infants perceive spectrally modified speech, one that is closely linked to the infant’s stage of native-language attunement. This research provides a solid foundation on which to conduct further research with HI infants and offers preliminary suggestions with regard to amplification and intervention to ensure that HI infants have the opportunity to emulate the native-language attunement process and subsequently achieve language development outcomes comparable with their NH peers. / Doctor of Philosophy (PhD)

Being given the diagnosis of a disability generally affects an individual's emotional state, however, this has not previously been investigated with respect to audiology and the diagnosis of hearing loss. The first aim of this study was to describe some of the common initial reactions to the diagnosis of hearing loss (HL). An awareness of these emotional reactions will aid audiologists in counselling their patients. Counselling occurs at the time of the diagnosis and throughout the aural rehabilitation process. However, counselling tuition is currently not provided for audiology students at New Zealand universities and there are few professional development courses for practicing audiologists. The second aim of this study was to evaluate current audiological counselling services and ascertain the impact on patients' decisions to get hearing aids (HAs). To accomplish these aims, 27 adults who had been newly-diagnosed with a HL completed an initial reaction questionnaire, partook in an interview which followed up on the questionnaire, and subsequently completed a second questionnaire at least three weeks later. There were two versions of the second questionnaire, depending on whether they had chosen to have HA(s) fitted. The results found that the common emotions reported were a sense of loss, sadness and resignation, as well as relief. Furthermore, an individual's level of optimism tended to decrease in response to the hearing test result. The ratings of the audiological counselling services were positive and seemed not to significantly influence the individual with respect to their decision to purchase HAs. The two areas of audiological counselling which could be improved related to how the audiologist explained the HL, particularly in relation to the individual's life, and also the provision of information to patients prior to the fitting of the HA. In addition to the data that was collected in relation to these aims, information was collected with respect to patients' perceptions of their HL prior to the hearing test, their interpretation of the hearing test results, and also how the patient's significant other responded to the diagnosis. The information from this study will be useful for equipping audiologists, both new graduates and those with more experience, to provide optimal audiological care for their patients.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Thesis (M. Communication Pathology)--University of Pretoria, 2004. / Includes bibliographical references.