Cochlear implant (CI) users have traditionally reported less enjoyment and have performed more poorly on tasks of music perception (timbre, melody and pitch) than their normal hearing (NH) counterparts. The enjoyment and perception of music can be affected by the MAP programmed into a user’s speech processor, the parameters of which can be altered to change the way that a CI recipient hears sound. However, finding the optimal MAP can prove challenging to clinicians because altering one parameter will affect others. Until recently the only way to find the optimal MAP has theoretically been to present each potential combination of parameters systematically, however this is impractical in a clinical setting due to the thousands of different potential combinations. Thus, in general, clinicians can find a good MAP, but not necessarily the best one. The goal of this study was to assess whether a Genetic Algorithm would assist clinicians to create a better MAP for music listening than current methods. Seven adult Nucleus Freedom CI users were assessed on tasks of timbre identification, melody identification and pitch-ranking using their original MAP. The participants then used the GA software to create an individualised MAP for music listening (referred to as their “GA MAP”). They then spent four weeks comparing their GA and original MAPs in their everyday life, and recording their listening experiences in a listening diary. At the end of this period participants were assessed on the same timbre, melody, and pitch tasks using their GA MAP. The results of the study showed that the GA process took an average of 35 minutes (range: 13-72 minutes) to create a MAP for music listening. As a group, participants reported the GA MAP to be slightly better than their original MAP for music listening, and preferred the GA MAP when at the cinema. Participants, on average, also performed significantly better on the melody identification task with their GA MAP; however they were significantly better on the half-octave interval pitch ranking task with their original MAP. The results also showed that participants were significantly more accurate on the single-instrument identification task than the ensemble instrument identification task regardless of which MAP they used. Overall, the results show that a GA can be used to successfully create a MAP for music listening, with two participants creating a MAP that they decided to keep at the conclusion of the study.

Speech perception outcomes for people with a prelingual hearing loss, implanted with a cochlear implant in adolescence or adulthood, are characterized by a large degree of variability. Research findings indicate that some recipients do very well and gain significant open set speech perception skills, whilst a large percentage show little or no change in open set speech results, post implant. In studies to-date, mean speech perception scores were typically substantially poorer than those recorded for implant recipients with a postlingual hearing loss. Despite this, the majority of recipients with a prelingual hearing loss implanted with a cochlear implant in adolescence or adulthood reported satisfaction with their implant and used it regularly. Although there have been a number of studies in the area, none has taken a holistic approach and investigated both objective and subjective outcomes for a large group of participants. In addition, no study has employed a multiple regression analysis to investigate which characteristics were associated with speech perception outcomes in people with a prelingual hearing loss implanted with a cochlear implant in adolescence or adulthood. The objectives of the study were to examine speech perception and other outcomes in people with a bilateral prelingual or perilingual hearing loss, implanted with a cochlear implant as an adolescent or adult, and to investigate prognostic factors associated with positive outcomes. The design consisted of a retrospective review of both speech perception outcomes and other outcomes for 38 recipients, diagnosed with a bilateral hearing loss before age 3, and implanted with a cochlear implant at 14 years or older. There were 24 females and 14 males and the average age at initial stimulation was 33 years. All participants were implanted with a Nucleus device at a private audiology clinic (Attune). Four questionnaires were completed by approximately half of the participants – Glasgow Benefit Inventory (GBI); International Outcome Inventory (IOI-CI); Study Questionnaire; and the Hearing Abilities and Quality of Life Scale. The Study Questionnaire was developed specifically for this project and investigated satisfaction, benefit and advantages/disadvantages of the implant. The Hearing Abilities and Quality of Life Scale was developed by Attune and was completed by recipients pre and post implant. It evaluated the ability to understand conversation in different situations, environmental awareness, safety concerns, involvement in social activities and impact of the hearing loss on relationships. Approximately one third of participants scored between 30 and 90% on the CID/ CUNY test administered via CD post implant and approximately one fifth scored over 90%. The mean score on the CID/CUNY test administered via CD was 8% pre implant and 48% post implant. Over 80% of recipients used their device more than 8 hours a day and all recipients reported being satisfied with it. Three factors accounted for 65% of the variance on the open set sentence test score, post implant. These were stable versus progressive loss, mode of communication in childhood and time without a hearing aid on the implant ear. For the purposes of this research, a ‘stable’ loss was defined as a bilateral severe to profound hearing loss at diagnosis and a ‘progressive’ loss was one that deteriorated to this degree at some point after diagnosis. The findings from this study reveal that a cochlear implant is a viable option for adults and adolescents with a prelingual hearing loss. The majority of participants gained benefit from the device and were satisfied with it. In addition, a substantial number gained good open set speech perception ability, post implant. Consistent with previous studies, there was large intersubject variability in speech scores. The recipients who had a progressive loss, used oral communication in childhood and wore a hearing aid on the implant ear up to the time of surgery were more likely to obtain better speech perception outcomes.

Existing music questionnaires have shown that postlingually deafened adult cochlear implant (CI) users generally find music to be less enjoyable following implantation. However, they did not investigate, in detail, which factors influence CI users’ music listening enjoyment, nor did they examine the approach a music training program should take. In order to obtain such information, a questionnaire, the University of Canterbury Music Listening Questionnaire (UCMLQ), was developed. The UCMLQ investigated: (i) the effect of implantation on CI users’ music listening enjoyment (determined by comparing the levels of enjoyment experienced post-implantation to prehearing loss, and just before implantation); (ii) the effect of a hearing aid in the unimplanted ear on CI users’ music perception and appreciation; (iii) the effect of timbre on music listening enjoyment whereby respondents will be asked to rate the pleasantness and naturalness of common instruments and voices, and also, give ratings on the instruments’ sound quality based on what they expect these instruments to sound to a person with normal hearing; (iv) whether respondents have a preference for a particular musical style (e.g. Country and Western, Jazz, Classical, etc); (v) whether respondents’ have a preference for, firstly, low-pitched versus high-pitched instruments/voices; secondly, music with instruments-only, voice-only, or both instruments and voice; and lastly, music with smaller number of performers versus greater number of performers; (vi) practical methods or ‘tips’ for enhancing everyday music listening enjoyment were collated; and finally, (vii) respondents were asked for their views and opinions on the content and logistics of a ‘take-home’ MTP for improving their music listening enjoyment. One-hundred postlingually deafened adult CI users, ranging in age from 18 to 88 years (mean = 62.1, SD = 17.1), completed the UCMLQ. All respondents used a Nucleus CI24 implant and the ACE speech processing strategy. Results showed that following implantation, respondents generally found music to be less enjoyable but they also preferred certain types of instruments and music: (i) low-frequency instruments over high-frequency instruments; (ii) certain instruments (e.g. the guitar) over others (e.g. brass instruments); (iii) smaller numbers of performers as opposed to larger numbers; (iv) Country and Western music as opposed to Pop/Rock, Jazz, Classical-small group, and Classical-orchestra; and (v) music with a slow rhythm/beat, and words. A comparison of the ratings given by CI and Hearing Aid (CI+HA) users and CI-only users also revealed that CI+HA users felt that they were significantly more able to follow the melody-line of musical styles, identify these styles, and they also rated musical styles to sound significantly ‘more normal’ than the CI-only users did. However, no statistically significant difference was found between the two groups’ (CI+HA users versus CI-only users) ratings for common instrumental sounds. In regards to respondents’ interest in partaking in a ‘take-home’ music training program (MTP), 54% of respondents stated that they would be interested in undertaking one. Respondents also indicated that the MTP should focus on improving their ability to recognise tunes, in particular, tunes known before implantation, and commonly-known tunes, and the MTP should offer a wide range of musical styles. In addition, training sessions should be of 30- minutes duration, 2 times per week, and the MTP should come in the form of a DVD with subtitles. Overall, this study collected information which not only helps us to better understand CI users’ appreciation of music but also could be used in the shaping and development of a future MTP.

Diss. (sammanfattning) Linköping : Univ., 2001. / Härtill 4 uppsatser.

Thesis (Ph.D.)--University of Melbourne, Dept. of Otolaryngology, 2005. / Typescript. Author's name on spine: B.Y. Cahyono. Includes bibliographical references (p. 185-220).

Thesis (Ph.D.)--University of Melbourne, Dept. of Otolaryngology (Eye & Ear Hospital), 2006. / Typescript. Includes bibliographical references (leaves 238-253).

Thesis (Ph.D.)--University of Texas at Dallas, 2008. / Includes vita. Includes bibliographical references (leaves 95-105)

Thesis (M. Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 37-40).

Thesis (M.Ed.)--York University, 2009. Graduate Programme in Education. / Typescript. Includes bibliographical references (leaves 42-44). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR51588

Zugl.: München, Universiẗat, Diss., 2009.