• The Journal of the Acoustical Society of Korea
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• v.26 no.1
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• pp.8-15
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• 2007

Speech intelligibility of the eavesdropping sound is investigated on a acoustic cavity - glass window coupled system. Using MLS (Maximum Length Sequency) signal as a sound source, acceleration and velocity responses of the glass window are measured by accelerometer and laser doppler vibrometer. MTF (Modulation Transfer Function) is used to identify tile speech transmission characteristics of the cavity and window system. STI (Speech Transmission Index) based upon MTF is calculated and speech intelligibility of the vibration sound of the glass window is estimated. Speech intelligibilities by the acceleration signal and the velocity signal are compared. Finally, intelligibility of the conversation sound is confirmed by the subjective test.

• The Journal of the Acoustical Society of Korea
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• v.30 no.8
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• pp.468-473
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• 2011

Speech may not be clearly understandable in the room that is highly reverberant, due to the loss of consonants intelligibility. Therefore, it is very important to obtain a high sound pressure level of direct sound in reverberant room. A properly designed sound reinforcement system can not provide the good speech intelligibility without the absorption treatments of walls. With using the highly directional speaker, we can transmit the sound energy into only the areas where people are sitting. This can be help to improve the speech intelligibility. In this paper, even in reverberant rooms, it will be shown that the good speech intelligibility can be obtained by only the directivity control of speaker without the room treatment. Also, it would be more improved by the properly room tuning using an equalizer.

• Proceedings of the Acoustical Society of Korea Conference
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• 1987.11a
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• pp.34-38
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• 1987

• 재활복지
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• v.20 no.3
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• pp.67-82
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• 2016

The purpose of this study was to investigate relation and effect of PCC(Percentage of Correct Consonant) and nasalance score on the speech intelligibility and acceptability in adults with dysarthria by reading task of standardized passage. Ten adults with dysarthria and sixteen normal adults were participated in this study. PCC and nasalance score were measured through reading task of standardized passage. And, speech intelligibility and acceptability were examined using visual analogue criteria. The result of the study was as follows. First, the nasalance score of adults with dysarthria group is significantly higher than normal adults group in reading sample by standardized passage. Second, the PCC, speech intelligibility and acceptability shows significant correlation. However, the nasalance score doesn't show significant corelation with speech intelligibility and acceptability. These results suggest that PCC is closely related to speech intelligibility and speech acceptability, but nasalance score is not related to speech intelligibility and speech acceptability.

• The Journal of the Acoustical Society of Korea
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• v.35 no.4
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• pp.319-329
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• 2016

The present study was to test if breathing training in melodic intonation therapy (MIT) ameliorated the articulation intelligibility of Broca's aphasics or not. The experimental group did breathing training (2 stages) that preceded the MIT. In order to evaluate the efficacy of the MIT intervention, the VOT (Voice Onset Time), the TD (Total Delay), the voice sound intensity and the expiratory volume of the subjects, closely associated with articulation intelligibility were measured before and after the intervention. It was shown that, in the experimental group after the MIT intervention, the VOT and TD were increased on bilabial/p/, alveolar consonant /t/, and soft palatal /k/(p < 0.05), but no significant differences were found on affricate /c/ and fricative /s/(p > 0.05). In the control group, no significant increases in the VOT and TD were observed on all articulation points(p > 0.05). The voice sound intensity which influences the verbal articulation increased in the experimental group after the intervention(p < 0.05), whereas no significant changes were observed in the control group. In conclusion, the breathing training in the MIT was found to result in improving the articulation intelligibility of Broca's aphasiacs.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.703-708
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• 2011

In this paper, most of the church except for a large church has accommodated many audience to install a balcony floor in a small space. therefore, dead zone and dislocated sound image localization is made due to this under-balcony seats. This paper propose that the problems of dead zone and dislocated sound image localization could be solved using computer simulation in the view of practical side. The economical computer simulation tool, Mapp online that can be found easily was used to the specified church. Installation a sub speaker for dead zone and -10 dB power control of the sub speaker to main speaker power for dislocated sound image localization was proposed. Computer simulation result shows that the value of definition for area was improved from "Normal" to "Very Good" which means about 52% improvement.

• Journal of KSNVE
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• v.10 no.2
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• pp.240-246
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• 2000

One of the widely accepted methods for evaluating the interior sound quality of automobiles is Articulation Index(AI). The AI actually measures the articulation level of the sound in the vehicle cabin as passengers talk to one another. In this study, the effect of two different absorption materials inside the cabin on AI has been investigated by ray-tracing method : one is firewall, the other is celling. It turns out that the back seat location is found to be strongly dependent on the type of absorption materials treated at the celling, since the sound absorbing area is different due to the location and the firewall is situated in the "Reverberation Radius". The proposed methdo could be used to improve the sound quality of automobiles at the design stge.sign stge.

• Proceedings of the Acoustical Society of Korea Conference
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• 1993.06a
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• pp.93-97
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• 1993

본 논문은 한국어 문어변환(TTS:Text-to-Speech) 시스템내에서의 음성합성시 음질 및 자연성 개선을 위한 연구 결과이다. 합성음 평가방법으로는 한국어 발음대사전에 수록된 빈도수 순위대로 추출한 음절(V형: 19개, CV형:80개, VC형:30개, CVC형: 100개, 총 229개)을 대상으로 규칙합성시킨 1음절어(합성음절수:229개)중 음절유형별로 15개씩 총 60개 음절을 20초간 3회 반복음의 녹음 테이프를 작성한 합성음에 대하여 사전지식이 없는 임의의 그룹을 선정하여 이해도, 명료도, 잡음감, 자연성 등 4 가지 항목에 대하여 오피니온 평가를 수행한 결과를 제시하였다.

• Proceedings of the Acoustical Society of Korea Conference
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• 1995.06a
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• pp.211-215
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• 1995

명료하고 자연스러운 한국어 음성을 생성하기 위하여 다중대역 여기신호를 이용한 음성 합성 시스팀을 제안한다. 분석계에서는 켑스트럼 파라미터를 사용하여 유성/무성 판별 스펙트럼을 이용한 유/무성 구간 자동판별법을 제안하고, 현재 단순 임펄스와 백색잡음만으로도 구성된 음원과 간단한 유성/무성 판별로 구동되어지는 합성음의 음질상의 한계를 개선하기 위하여 합성계에서는 음질개선 방안으로 유성음 구동시 다중대역 여기신호를 도입하여 합성시 이용한다. 제안된 방법에 대한 청취실험을 한 결과, 유성음 부분 특히 잡음이 많이 섞여 있는 유성음화 마찰음과 모음의 천이부분 등에서 일반적으로 사용되고 있는 간단한 유성/무성 파라미터를 사용한 합성음에 비하여 다중대역 여기신호를 사용한 합성음의 명료도가 매우 우수함을 확인하였다.

• The Journal of the Acoustical Society of Korea
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• v.28 no.2
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• pp.127-134
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• 2009

In this study, possibility of the laser eavesdropping is investigated on the window glasses with various thicknesses, Glass windows are excited by maximum length sequency (MLS) signal and the vibration sound is detected by a laser doppler vibrometer. From the detected sound, speech intelligibility is objectively estimated. Speech transmission index (STI), which is based on the modulation transfer function (MTF). is calculated for the estimation. Finally, disturbing wave effect on the speech intelligibility is analysed by using an outside speaker and a window shaker attached on the glass window. The purpose of the study is to estimate the possibility of remote eavesdropping by the laser sensor and to evaluate the performance of the homemade window shaker to protect from the remote eavesdropping.