• Journal of Biomedical Engineering Research
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• v.31 no.6
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• pp.417-426
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• 2010

We present a speech processing strategy incorporating instantaneous frequency (IF) encoding for the enhancement of melody recognition performance of cochlear implants. For the IF extraction from incoming sound, we propose the use of a Teager energy operator (TEO), which is advantageous for its lower computational load. From time-frequency analysis, we verified that the TEO-based method provides proper IF encoding of input sound, which is crucial for melody recognition. Similar benefit could be obtained also from the use of a Hilbert transform (HT), but much higher computational cost was required. The melody recognition performance of the proposed speech processing strategy was compared with those of a conventional strategy using envelope extraction, and the HT-based IF encoding. Hearing tests on normal subjects were performed using acoustic simulation and a musical contour identification task. Insignificant difference in melody recognition performance was observed between the TEO-based and HT-based IF encodings, and both were superior to the conventional strategy. However, the TEO-based strategy was advantageous considering that it was approximately 35% faster than the HT-based strategy.

• Journal of Music and Human Behavior
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• v.12 no.2
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• pp.1-18
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• 2015

The purpose of this study was to compare the vocal characteristics of 40 adults with and without cerebral palsy (CP), upon presentation of three speech tasks (i.e., reading, chanting, and singing). The Praat program was utilized to generate data on fundamental frequency, voice intensity, jitter, and shimmer. The results of the analysis revealed no significant differences on fundamental frequency and intensity. However, both groups showed significant decreases in jitter and shimmer when engaged in singing tasks. The analysis of group differences indicated that adults with CP showed significantly higher variation scores on jitter and shimmer than the group without CP, and the difference on jitter and shimmer became greater during rhythmic chanting. In terms of jitter variation, the interaction effects according to the groups and types of speech tasks were greater, demonstrating the differences between the two groups. This study can be utilized as a basic research, regarding changes in vocal characteristics of adults with CP according to different musical speech tasks.

• Phonetics and Speech Sciences
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• v.6 no.2
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• pp.37-45
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• 2014

The purpose of this study was to determine whether the Korean Singing Voice Handicap Index (K-SVHI) was suitable for singers in other genres than vocal music to assess their vocal problems subjectively. Twenty six college students majoring in vocal music and twenty six students majoring in applied music were included in the study. They were divided into G0 and G1 in voice quality using the GRBAS scale during the tasks of singing. K-SVHI was divided into three sub-areas (Physical, Functional, and Emotional). In the singing task, both groups showed no significant difference between K-SVHI scores by G scale. In the reading task, the vocal music group had significantly higher K-SVHI in G0 than in G1 in K-SVHIs by G scale, while the applied vocal music group had significantly higher K-SVHI in G1 than in G0. Also, the two groups were not significantly different in G0, G1 in the singing task while the vocal music group showed higher K-SVHI than the applied vocal music group in G0 in the reading task. In addition, the vocal music group had higher K-SVHI than the applied vocal music group in G1 in both tasks. As comparing by groups in three sub-areas of K-SVHI, significant differences were found in the Emotional and Functional area. Those results showed that singers felt their voice problems differently by musical genres, which means that K-SVHI may not be a proper tool for evaluating voice handicap of singers in diverse voice music genres.