• 대한의용생체공학회:의공학회지
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• 제31권6호
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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.

• 인간행동과 음악연구
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• 제12권2호
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• pp.1-18
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• 2015

본 연구의 목적은 뇌성마비 성인과 일반 성인에게 각각 동일한 발화과제(일반, 리듬, 선율 발화)를 제공한 뒤 집단(일반 및 뇌성마비 성인)과 발화과제에 따라 어떠한 음성 특성이 나타나는지 알아보는 것이다. 연구대상은 뇌성마비 성인 20명과 일반 성인 20명이며 프라트(Praat) 프로그램을 사용하여 발화과제에 따른 기본주파수, 음성강도, 주파수 변동률, 진폭 변동률수치를 구하였다. 각 집단의 발화 과제에 따른 음성 특성 분석 결과, 기본주파수와 음성강도의 경우 두 집단 모두 유의한 차이는 없었으나 주파수 변동률 및 진폭 변동률의 경우 일반성인집단과 뇌성마비성인집단 모두 선율 발화 시 유의하게 가장 낮은 수치를 보였다. 집단에 따른 차이를 분석한 결과, 뇌성마비성인집단의 주파수 변동률 및 진폭 변동률이 일반성인집단에 비해 유의하게 높은 수치를 보였다. 또한 일반성인집단과는 달리 뇌성마비성인집단의 경우 리듬 발화 시 주파수 변동률 및 진폭 변동률 수치가 가장 높게 나타났으며 주파수변동률의 경우 집단과 발화과제 종류에 따른 상호작용 효과가 유의해 두 집단 사이에 상이한 양상이 발견되었다. 본 연구는 발화 시 적용된 음악요소에 따라 나타나는 즉각적 음성 특성에 대한 정보를 제공해주는 기초자료로 사용될 수 있다.

• 말소리와 음성과학
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• 제6권2호
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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.