• 말소리와 음성과학
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• 제6권3호
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• pp.57-62
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• 2014

The present study was performed to investigate and discuss the aerodynamic characteristics of whispered and normal speech during reading paragraph tasks. 39 normal females(18-23 yrs.) read 'Autumn' paragraph with whispered and normal phonation. Their readings were recorded and analyzed by 'Running Speech' in Phonatory Aerodynamic System(PAS) instrument. As results, during whispered speech, the total duration was longer and the numbers of inspiration were more frequently shown than normal speech. The Peak expiratory and inspiratory rate were higher in normal speech, but the expiratory and inspiratory volume were higher in whispered speech. By correlation analysis, both whispered and normal speech showed significantly high correlation between total duration and expiratory/inspiratory airflow duration; numbers of inspiration and inspiratory airflow duration; expiratory and inspiratory volume. These results show that whispered speech needs more respiratory effort but shows poorer aerodynamic efficacy during phonation than normal speech.

• Archives of Plastic Surgery
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• 제32권3호
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• pp.375-380
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• 2005

Furlow palatoplasty has been favored by many plastic surgeons as the primary treatment for the velopharyngeal insufficiency associated with submucous cleft palate. The purpose of this article is to introduce an efficacy of Furlow palatoplasty and speech therapy performed on patients who were diagnosed belatedly as having submucous cleft palates. From 2002 to 2004, four submucous cleft palate patients over 5 years of age with velopharyngeal insufficiency received Furlow palatoplasty. The patients were evaluated through the preoperative perceptual speech assessment, nasometry, and videonasopharyngoscopy. Postoperatively, two patients achieved competent velopharyngeal function in running speech. One of the remaining two could achieve competent velopharyngeal function with visual biofeedback speech therapy and the other could not use her new velopharyngeal function in running speech because of her age. Speech therapy can correct the articulation errors and thus improve the velopharyngeal function to a certain extent by eliminating some compensatory articulations that might have an adverse influence on velopharyngeal function. This study shows that Furlow palatoplasty can successfully correct the velopharyngeal insufficiency in submucous cleft palate patients and speech therapy has a role in reinforcing surgical result. But age is still a restrictive factor even though surgery was well done.

• 음성과학
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• 제10권2호
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• pp.77-84
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• 2003

In this research, we seek the beginning of the speech and detect the stationary speech region using lip information. Performing running average of the estimated speech signal in the stationary region, we reduce the effect of musical noise which is inherent to the conventional MlMSE (Minimum Mean Square Error) speech enhancement algorithm. In addition to it, SFM (Spectral Flatness Measure) is incorporated to reduce the speech signal estimation error due to speaking habit and some lacking lip information. The proposed algorithm with Wiener filtering shows the superior performance to the conventional methods according to MOS (Mean Opinion Score) test.

• 음성과학
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• 제6권
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• pp.219-233
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• 1999

This paper presents a real-time implementation of a speaker independent speech recognition system based on a discrete hidden markov model(DHMM). This system is developed for a car navigation system to design on-chip VLSI system of speech recognition which is used by fixed point Oak DSP core of DSP GROUP LTD. We analyze recognition procedure with C language to implement fixed point real-time algorithms. Based on the analyses, we improve the algorithms which are possible to operate in real-time, and can verify the recognition result at the same time as speech ends, by processing all recognition routines within a frame. A car noise is the colored noise concentrated heavily on the low frequency segment under 400 Hz. For the noise robust processing, the high pass filtering and the liftering on the distance measure of feature vectors are applied to the recognition system. Recognition experiments on the twelve isolated command words were performed. The recognition rates of the baseline recognizer were 98.68% in a stopping situation and 80.7% in a running situation. Using the noise processing methods, the recognition rates were enhanced to 89.04% in a running situation.

• The Journal of the Acoustical Society of Korea
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• 제25권3E호
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• pp.123-130
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• 2006

The adaptive echo canceller (AEC) has become an important component in speech communication systems, including mobile station. In these applications, the acoustic echo path has a long impulse response. We propose a running-average least mean square (RALMS) algorithm with a detection method for acoustic echo cancellation. Using colored input models, the result clearly shows that the RALMS detection algorithm has a convergence performance superior to the least mean square (LMS) detection algorithm alone. The computational complexity of the new RALMS algorithm is only slightly greater than that of the standard LMS detection algorithm but confers a major improvement in stability.

• 대한음성학회지:말소리
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• 제50호
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• pp.99-110
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• 2004

The normal transmission characteristics of sound are hardly obtained due to the various noises and structural factors in a running car environment. It is due to the channel distortion of the original source sound recorded by microphones, and it seriously degrades the performance of the speech recognition in real driving environments. In this paper we analyze the degree of intelligibility under the various sound distortion environments by channels according to driving speed with respect to speech transmission index(STI) and compare the STI with rates of speech recognition. We examine the correlation between measures of intelligibility depending on sound pick-up patterns and performance in speech recognition. Thereby we consider the optimal location of a microphone in single channel environment. In experimentation we find that high correlation is obtained between STI and rates of speech recognition.

• 말소리와 음성과학
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• 제6권4호
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• pp.181-187
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• 2014

The present study was performed to investigate the characteristics of breath groups while reading paragraph in normal adults and adult patients with voice disorders. 10 normal females(avr. 20.6 yrs.), 10 young voice disorder females(avr. 33.5 yrs., P1 group), and 10 old voice disorder females(avr. 56.3 yrs., P2 group) read a paragraph of 210 syllables. By using the 'Running Speech' program of the Phonatory Aerodynamic System(PAS), total duration, numbers of breath groups, duration per breath group, and numbers of syllables per breath group were measured, and their correlations with aerodynamic measurement results of reading were analyzed. As a result, in total duration, numbers of breath groups, normals scored highest and P2 group speakers, lowest. Normals showed the longest duration per breath group which was not significant. P2 group speakers showed the highest numbers of syllables per breath group. Correlation analysis showed significantly high correlation scores of total duration and expiratory airflow; numbers of breath groups and inspiratory volume.

• 한국음향학회지
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• 제19권5호
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• pp.3-8
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• 2000

본 논문은 주행중인 자동차 환경에서의 음성인식에 대하여 연구하였다. 여기에서 사용한 기준패턴(reference pattern)은 DMS(Dynamic Multi-Section)이며, 인식율을 높이기 위하여 2모델을 제안하였다. 또한 가변적인 차량의 잡음환경에 강인하기 위하여 일반주행(80km/h 이내), 고속주행(80km/h 이상)등으로 나누었으며 차량의 잡음에 따라 자동으로 선택하도록 하였다. 음성의 특징 벡터와 인식 알고리즘은 PLP(Perceptual Linear Predictive) 13차와 OSDP(One-Stage Dynamic Programming)를 사용하였다. 그리고 핸드폰을 사용하는 운전자의 안전을 위하여 음성으로 전화를 걸 수 있도록 하는 전화번호 등록 및 제어기능의 Voice Dialing 기능을 추가하였다. 실험결과 주행중인 자동차 환경에서 자주 사용되는 차량 편의장치 제어명령 33개에 대하여 중부, 영동 고속도로(시멘트 도로 80km/h이상)에서 남성 화자독립 89.75%의 인식율을 구하였으며, 경부고속도로(아스팔트 도로 80km/h이상)에서는 남성화자독립 92.29%의 인식율을 구하였다.

• 융합신호처리학회논문지
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• 제13권1호
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• pp.19-25
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• 2012

An adaptive system is a well-known method for removing noise from noise-corrupted speech. In this paper, we perform a least mean square (LMS) based on wavelet adaptive algorithm. It establishes the faster convergence rate of as compared to time domain because of eigenvalue distribution width. And this paper provides the basic tool required for the FIR algorithm whose algorithm reduces the arithmetic complexity. We consider a new fast short-length running FIR structure in discrete wavelet adaptive algorithm. We compare FIR algorithm and short-length fast running FIR algorithm (SFIR) to the proposed fast short-length running FIR algorithm(FSFIR) for arithmetic complexities.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2004년도 춘계 학술대회 발표논문집
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• pp.231-234
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• 2004

This paper describes an efficient method for improving the noise-robustness in speech recognition in a running car by considering wind noise. In driving car, mainly three kind of noises engine noise, tire noise and wind noise, are severely affect recognition performance. Especially wind noise is an important factor in driving car with window opened. We analyzed wind noise in various driving conditions that are 60, 80, 100 km/h with window fully opened, window half opened. We clarified that the recognition rate is significantly degenerated when the wind noise components in the frequency range above 200 Hz are large. We developed a preprocessing method to improve the noise robustness despite of wind noise. We adaptively changed the cutoff frequency of the front-end high-pass filter from 100 through 200 Hz according to the level of the wind noise components. By this method, the recognition rate is considerably improved for all kind of driving conditions