• 음성과학
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• 제10권4호
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• pp.201-219
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• 2003

Background: The perceptual assessment is generally performed by the voice specialist. The objective evaluation is performed in a voice laboratory. Research in voice laboratories has generated a variety of different objective tests and parameters. The perceptual evaluation is one of the most controversial topics in voice research. Review of literature reveals a wide variety of rating scales and reliability data fluctuating from study to study. Unfortunately, there is no widely accepted valid method for classifying voice disorders and assessing outcome after voice treatment. Objectives: The goals of this research were to identify important objective acoustic parameters of vocal quality, and to establish an objective and quantitative correlate of the perceived vocal quality. Materials and Methods : We evaluated the voice analyzed data from 122 dysphonic patients and 20 normal volunteers. A computerized speech lab. 4300B(CSL) was used to carry out the analysis of each voice sample. Results: Three dysphonia severity indices(DSI) were created using discriminant analysis. DSI is based on the weighted combination of the following selected set of acoustic parameters: absolute jitter(Jita in us), smoothed pitch period perturbation (sPPQ in %), amplitude perturbation quotient(APQ in %), soft phonation index(SPI), average fundamental frequency(Fo in Hz), lowest fundamental frequency(Flo in Hz), and smoothed amplitude perturbation quotient(sAPQ in %). The DSI, being the discriminating rule calculated by the logistic regression, consists of three equation based on statistically significant acoustic parameters. Three DSI were created to reflects best the degree of hoarseness as expressed by G from the GRBAS scale. The more positive this DSI is for a patient, the worse the vocal quality. The more it is negative, the better it is. The effect of sex is included implicitly in the DSI-1 and DSI-2, so that a separate DSI-1 and DSI-2 for males and females need not be used. The DSI is objective because no perceptual input is required for its calculation. Conculsion : This research demonstrates that the voice function values calculated from three different multivariate objective dysphonia severity indices are significantly associated with subjective voice assessments. These multivariate objective dysphonia severity indices may be appropriate for use in clinical trials and outcomes research on treatment effectiveness for voice disorders.

• 대한후두음성언어의학회지
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• 제9권1호
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• pp.22-26
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• 1998

Uvulopalatopharyngoplasty(UPPP) is one of the most popular surgical procedure for the treatment of obstructive sleep apnea syndrome(OSAS) occurring at the level of oropharynx. However, voice changes after UPPP have been a challenging issue for the professional voice users, because even minor changes in voice quality or articulation may be critical to professional singers, teachers, and so on. Several acoustic changes after UPPP have been proposed. However, based on the authors understanding, there is no report about voice changes after UPPP in Korean. We measured the first, second and third formant frequencies of /a/, /i/, /u/ phonations in 20 adult male patients who had undergone UPPP surgery, and the nasalances of Rabbit, Baby, and Mama passages. These parameters were measured preoperatively, at 1 month and 3 months after the operation. Any subjective voice changes were asked to be reported at the posto-perative visits. The third formant(F3) of /u/ phonation was significantly reduced at postoperative 1 month measurement. The nasalance of Mama passage was singnificantly increased at postoperative 3 months measurement. No one complained of subjective changes in voice quality, timbre, articulation or speech. Even though there are no complaints about postoperative voice changes subjectively, significant changes in the formant characteristics of certain vowel and changes in the nasality after UPPP require the clinicians to be mort cautious and careful in deciding UPPP for the professional voice users.

• 한국전자통신학회논문지
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• 제6권6호
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• pp.823-829
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• 2011

본 논문은 현재 상용화되어 국내에서 서비스가 제공되고 있는 무선 접속 시스템인 와이브로 네트워크를 통해서 패킷기반 음성 서비스가 제공되는 경우 예상되는 서비스 품질에 관한 것이다. 무선 환경에서 패킷기반 음성 서비스를 위한 체계적인 서비스 품질 관리 방안 수립을 위한 노력의 일환으로 이미 개발된 품질 측정 소프트웨어[2][3]를 이용하여 다양한 시나리오 하에서 음성 서비스의 품질을 측정하였다. 측정 결과의 분석을 통해서 현 시점에서 와이브로 네트워크를 통해서 음성 서비스가 제공될 경우 서비스 품질이 상당히 양호할 것임을 확인할 수 있었다. 추가적으로 무선 전송 환경의 변화가 음성 서비스의 품질에 미치는 영향을 알아보기 위한 또 다른 실험을 통해서 음성 서비스 품질의 급격한 저하 현상이 나타나는 무선 품질 지표의 값을 확인할 수 있었다.

• 한국전자통신학회논문지
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• 제7권2호
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• pp.249-255
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• 2012

본 논문은 현재 상용화되어 국내에서 서비스가 제공되고 있는 무선 접속 시스템인 HSDPA (High Speed Downlink Packet Access) 시스템을 통해서 패킷기반 음성 서비스가 제공되는 경우 예상되는 서비스 품질에 관한 것이다. 무선 환경에서 패킷기반 음성 서비스를 위한 체계적인 서비스 품질 관리 방안 수립을 위한 노력의 일환으로 이미 개발된 품질 측정 소프트웨어[2][3]를 이용하여 다양한 시나리오 하에서 음성 서비스의 품질을 측정하였다. 측정 결과의 분석을 통해서 현 시점에서 HSDPA 시스템을 통해서 음성 서비스가 제공될 경우 서비스 품질이 상당히 양호할 것임을 확인할 수 있었다. 추가적으로 무선 전송 환경의 변화가 음성 서비스의 품질에 미치는 영향을 알아보기 위한 또 다른 실험을 통해서 음성 서비스 품질의 급격한 저하 현상이 나타나는 무선 품질 지표의 값을 확인할 수 있었다.

• 대한후두음성언어의학회지
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• 제19권1호
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• pp.7-10
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• 2008

The early glottic cancers are traditionally treated by radiotherapy or endoscopic surgery. The excellent effectiveness of both treatment modalities for local control, larynx preservation, and disease specific death is similar. Therefore, functional voice outcome after treatment is one of the most important factors in the choice of treatment for early glottic cancer. To assess the functional outcomes and compare the voice quality in patients with early glottic cancer treated with curative intent with radiotherapy or laser cordectomy, we performed literature review. Most studies showed that the voice quality after radiation therapy is slightly better than that after laser cordectomy. Subanalysis according to types of laser cordectomy, however, indicates that voice quality depends on type of laser cordectomy. Especially, type I or type II laser cordectomy might be superior to other types of laser cordectomy and radiation therapy. We conclude that the laser cordectomy is a good surgical alternative for properly selected early glottic cancer including professional voice users.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권4호
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• pp.1006-1025
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• 2012

Improving the quality of service in IP networks is a major challenge for real-time voice communications. In particular, packet arrival-delay variation, so-called "jitter," is one of the main factors that degrade the quality of voice in mobile devices with the voice-over Internet protocol (VoIP). To resolve this issue, a receiver-based enhanced timing recovery algorithm combined with active jitter estimation is proposed. The proposed algorithm copes with the effect of transmission jitter by expanding or compressing each packet according to the predicted network delay and variations. Additionally, the active network jitter estimation incorporates rapid detection of delay spikes and reacts to changes in network conditions. Extensive simulations have shown that the proposed algorithm delivers high voice quality by pursuing an optimal trade-off between average buffering delay and packet loss rate.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1999년도 추계학술대회 논문집
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• pp.272-277
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• 1999

The necessity of voice recording device was increased using voice signal IC with designed LSI/VLSI. The control unit which developed here voice recorder has low power dissipation, portable, and comfortable using voice source. However, the Korea voice recorder abilities far behind of foreign products for its performance and size on sailing. So we used Chua circuit to improvement voice quality abilities after minimize power supply device and circuit by designing voice recording device into lower power dissipation power circuit.

• 대한음성학회지:말소리
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• 제55권
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• pp.119-130
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• 2005

The aim of this paper is to investigate some acoustical characteristics of the voice quality features from the emotional speech database. Six different parameters are measured and compared for 6 different emotions (normal, happiness, sadness, fear, anger, boredom) and from 6 different speakers. Inter-speaker variability and intra-speaker variability are measured. Some intra-speaker consistency of the parameter change across the emotions are observed, but inter-speaker consistency are not observed.

• 방송공학회논문지
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• 제18권5호
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• pp.771-774
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• 2013

본 연구는 감정상태와 음색특성의 관계를 확인하고, 추가로 cepstral 피쳐와 조합하여 감정인식을 진행하였다. Open quotient, harmonic-to-noise ratio, spectral tilt, spectral sharpness를 포함하는 특징들을 음색검출을 위해 적용하였고, 일반적으로 사용되는 피치와 에너지를 기반한 운율피쳐를 적용하였다. ANOVA분석을 통해 각 특징벡터의 유효성을 살펴보고, sequential forward selection 방법을 적용하여 최종 감정인식 성능을 분석하였다. 결과적으로, 제안된 피쳐들으로부터 성능이 향상되는 것을 확인하였고, 특히 화남과 기쁨에 대하여 에러가 줄어드는 것을 확인하였다. 또한 음색관련 피쳐들이 cepstral 피쳐와 결합할 경우 역시 인식 성능이 향상되었다.

• 음성과학
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• 제14권4호
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• pp.213-220
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• 2007

This study investigates the voice quality including F0, jitter, shimmer, and NHR for the children with cochlear implant (CI group) and those with normal hearing (NH group). The CI group was further classified two sub-groups depending upon the time of surgery (i.e. under four years vs. over four years). Three corner vowels (e.g. /a/, /i/, /u/) with extended vocalization were used and analyzed with Multi-Dimensional Voice Program (Kay Elemetrics, Model 4300). The statistics were made in two independent sample t-test with SPSS 11.5. The results can be summarized as follows: (1) The children with cochlear implanted before 4 years of age had very similar data with the NH group except for the vowel /a/. (2) The children with cochlear implanted after 4 years of age, however, indicated significant differences in Fo (/a/, /i/, /u/), Jitter (/e/), shimmer (/a/, /i/, /u/) and NHR(/a/) in all three vowels. It is concluded that the early CI surgery and the early intervention would be very important to maintain better voice quality.