A Computerized Pitch-Perception Training Program for the Hearing Impaired
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
Pitch perception plays an important role in both music and speech perception. Technological advancements in both hearing aids and cochlear implants (CIs) have helped to improve the speech perception abilities of the hearing impaired. However, pitch-related speech and music perception tasks remain a challenge to both hearing aid users and CI recipients. Existing research suggests that auditory training may be useful for enhancing these perceptual skills. This research developed a computerized pitch-perception training program and evaluated its effectiveness for improving the pitch-related speech and music perception skills of postlingually deafened adult CI recipients (CIA), postlingually hearing impaired adult hearing aid users (HA), and prelingually deafened pediatric CI recipients (CIC). The training program consisted of interactive listening activities using ‘real world’ natural musical instrument sounds and sung vowels. Two versions of the training program were developed, including the Version One training (V1T), which employed a fixed level approach and the Version Two training (V2T), which used an adaptive level approach. The training groups included 10 HA, eight CIA, and three CIC participants for V1T and seven HA, eight CIA, and two CIC participants for V2T. The normal hearing control groups included 19 normal hearing adults (NHA) and 12 normal hearing children (NHC). The training groups completed 10 weeks of training at home using the computerized pitch-perception training program. Both training and control groups undertook objective tests on various aspects of pitch-related speech and music perception before and after the training period. In addition, questionnaires were used to obtain the background information related to the participants’ music listening experiences. The training group also filled out a post-training evaluation questionnaire regarding their opinions about the efficacy of the training program. For the CIC group, some parts of the questionnaires were filled out by parents of the CIC participants only and some parts by both of the CIC participants and their parents. The results revealed that both CIA and HA groups showed an improvement following training with either V1T or V2T. However, V2T generally resulted in greater improvements than V1T. The pitch perception training from both versions of the program seems to have generalized to the performance of some pitch-related speech and music perception tasks. For both HA and CIA training groups, a statistically significant training effect on pitch-related speech and music perception test scores was observed (p < 0.05). A general improvement in the subjective perception of the trainees’ abilities in performing the pitch-related speech and music tasks was also observed. The CIC training groups failed to show a significant improvement in any of the perceptual tasks except for the CNC-phoneme test. Overall, more challenging tasks, especially tasks that required more focused attention, resulted in a more noticeable training effect than easy tasks. Results from the subjective evaluation carried out through a post-training evaluation questionnaire generally agreed with the improvements observed in the objective tests. Based on these findings and the feedback from the participants regarding the training program, a final version of the program is being formalized.