• The Journal of the Acoustical Society of Korea
• /
• v.17 no.2
• /
• pp.43-49
• /
• 1998

본 논문에서는 고성능 CELP 음성 압축기를 위한 "Boaseline 코드벡터"와 "Implied 코드벡터"로 구성되는 새로운 구조의 코드북을 제안한다. Implied 코드벡터는 피치 주기 이 전의 합성음으로부터 구하여지며 여기(勵起)신호의 피치 구조를 강화하여 합성음의 음질을 향상시킨다. Implied 코드벡터는 전달되지 않고 인코더 및 디코더에서 각각 합성음을 이용 하여 독립적으로 구하여진다. 또한 펄스와 랜덤 성분을 모두 가지는 복합 여기방식을 이용 하여 음질을 더욱 향상시킨다. 제안된 코드북 구조를 이용하여 10msec프레임을 가지는 8kbps CELP 음성 압축기를 설계하여 하나의 DSP칩에 실시간 구현 하였고, 이것의 성능을 SNRseg와 MOS로 측정하였다. 평균 SNRseg는 12.14dB로 CS-ACELP의 SNRseg보다 6dB 높고, 조용한 환경에서의 MOS는 3.80으로 G.729 CS-ACELP의 MOS보다 0.02 높다.

• Korean Journal of Bronchoesophagology
• /
• v.7 no.2
• /
• pp.140-145
• /
• 2001

Background and Objectives： Intractable aspiration in patients with impaired protective function of the larynx often results in multiple episode of aspiration pneumonia, repeated hospitalizations and expensive nursing care. The purpose of this study was to review the authors’experience and Patient outcome with the laryngotracheal separation (LTS) procedure. Materials and Methods A retrospective review of 9 patients who underwent LTS between 1996 and 2001 was conducted. Ages ranged from 3 to 72 years. Results : Seven patients were expected to have morbid aspiration as a consequence of acquired neurologic injuries and two were congenital neurologic injuries. Two patients had a postoperative fistula, which was well controlled with local wound care and minor procedure. Following LTS, aspiration was effectively controlled in all patients and four were able to tolerate a regular diet. Conclusion : LTS is a low-risk, successful. definitive procedure which decreases the potential for aspiration, pulmonary complication, hospitalizations and increases quality of life, especially in patent with irreversible upper airway dysfunction and Poor speech potential.

• Archives of Plastic Surgery
• /
• v.33 no.2
• /
• pp.161-167
• /
• 2006

After total glossectomy, recovery of swallowing and speech function can greatly improve quality of life. The reconstructed tongue must be thick enough to contact with the hard palate for articulation. If the free flap is denervation, it may procede to have atrophy postoperatively. Therefor it is difficult to maintain the tongue volume for a long period of time. To resolve this problem, we have used a innervated rectus abdominis musculocutaneous flap and maintaining the volume through a neurorrhaphy. 7 patients underwent immediate reconstruction using a reinnervated rectus abdominis musculocutaneous free flap in which included intercostal nerve was anastomosed to the remaining hypoglossal nerve. The reinnervated rectus abdominis musculocutaneous free flap has provided good tongue contour with sufficient bulk and shown no obvious atrophy in all patients even though postoperative 9 months later. Considering swallowing and articulation, we concluded that reinnervated rectus abdominis musculocutaneous flap is a viable method after total glossectomy

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.34S no.4
• /
• pp.50-56
• /
• 1997

In this paper, efficient quantization methods of line spectrum pairs (LSP) which has good performances and low complexity and memory are proosed for vocoder of mobile communication system. The adaptive quantization method utilizing the ordering property of LSP parameters is used in a scalar quantizer and a vector-scalar hybrid quantizer. The proposed scalar quantization algorithm needs 31 bits/frame to maintain the transparent quality of speech. The improved vector-scalar quantizer achieves an average spectral distortion of 1dB using 26 bits/frame. The proposed methods are evaluated in the channel errors and changed the predictor structure to maintain the robustness to channel errors.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2001.05a
• /
• pp.285-290
• /
• 2001

본 논문에서는 멀티미디어 서비스 요소 중의 하나인 VoIP(Voice Over Internet Protocol)망에서의 음성 품질에 대한 평가를 위해 VoIP망에서 송화자 내용- 발생과정에 있어서 어느 정도 완전히 표현되었는가를 나타내는 송화품질과 음성의 전송계를 통해 수화자에게 전달되는 과정에서 왜곡이나 잡음 등의 방해요인에 의해 열화되는 정도를 나타내는 전송품질, 그리고 수화자가 청각에서 신호처리 과정을 거친 송화자의 내용을 어느 징도 이해할 수 있는지를 나타내는 수화품질에 대한 주관적 방법을 평가한 후 통화품질을 측정한 내용을 분석하여 그 원인과 개선책에 대한 방법을 제시하고자 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 1998.06a
• /
• pp.95-98
• /
• 1998

본 논문에서는 코퍼스 기반 음성합성시 각 음성 세그머트의 에너지 정규화가 합성된 음성의 음질에 미치는 영향에 대하여 연구한다. 음성합성에 사용되는 음성 세그먼트를 실제 자연 음성 데이터로부터 추출된 것으로 다양한 발음세기를 가진다. 따라서 이들을 조합하여 만든 합성음성의 음질은 일반적으로 음량이 고르지 못하고 듣기에 부자연스럽다. 이러한 문제를 해결하기 위해 음성합성시 음성 세그먼트의 에너지를 정규화하는 방법을 제안하고 정규화방법으로 최대진폭 정규화방식을 사용하였다. 녹음환경이 비교적 일정한 코퍼스와 그렇지 않은 환경에서 녹음된 코퍼스를 사용하여 정규화 없이 합성한 음성의 음질과 정규화를 거쳐서 합성한 음성의 음질을 비교한다. 실험결과 음성 세그먼트의 에너지를 정규화한 경우 합성음성의 음질이 개선되었다.

• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.11
• /
• pp.79-82
• /
• 1997

In this paper, a body-worn type digital hearing aid (DHA) based on a dedicated DSP chip is developed. A fitting software running on a PC supported by the Win95 OS is also developed. The fitting protocol is based on the NAL-R procedure applied to eight frequency bands, but it is designed to support a curvilinear fitting to cope with the nonlinear perception of hearing-impaired listeners. Preliminary subjective tests regarding the speech intelligibility and perceived quality revealed that the new DHA could be of benefit to hearing aid users.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.25 no.2
• /
• pp.79-81
• /
• 2014

Spasmodic dysphonia (SD) is a chronic, focal, speech-induced, action-specific dystonia, resulting strained voice. Muscle tension dysphonia (MTD) may also result in a strangled, strained voice quality, usually as a result of compensation for underlying laryngeal disease such as glottal insufficiency. Patients with SD and MTD were suffered from the severely limiting people's communication, especially via telephone and in noisy backgrounds. SD is usually of the adductor type characterized by glottic contractions causing tightness and voice breaks, which is difficult to distinguish from MTD. In this review article, we present the characteritics and management of SD and MTD.

• Proceedings of the Acoustical Society of Korea Conference
• /
• 1994.06a
• /
• pp.1070-1075
• /
• 1994

This paper describes the method for designing loudness ratings as transmission quality for ISDN telephone connected to fully digital network. To design the desirable loudness ratings for ISDN telephone, the model system of digital speech communication for subjective test is developed and opinion tests for establishing the optimal CODEC input level, the range of overall loudness rating, and sidetone masking rating are performed. As the results, the desirable ranges of loudness ratings are proposed as 6 to 8dB for sending, 0 to 2dB for receiving, and 10 to 14dB for sidetone masking rating.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.4 no.4
• /
• pp.374-385
• /
• 2012

The indoor noise of a ship is usually determined using the A-weighted sound pressure level. However, in order to better understand this phenomenon, evaluation parameters that more accurately reflect the human sense of hearing are required. To find the level of the satisfaction index of the noise inside a naval vessel such as "Loudness" and "Annoyance", psycho-acoustic evaluation of various sound recordings from the naval vessel was performed in a laboratory. The objective of this paper is to develop a single index of "Loudness" and "Annoyance" for noise inside a naval vessel according to a psycho-acoustic evaluation by using psychological responses such as Noise Rating (NR), Noise Criterion (NC), Room Criterion (RC), Preferred Speech Interference Level (PSIL) and loudness level. Additionally, in order to determine a single index of satisfaction for noise such as "Loudness" and "Annoyance", with respect to a human's sense of hearing, a back-propagation neural network is applied.