• 말소리와 음성과학
• /
• 제13권2호
• /
• pp.19-25
• /
• 2021

설측음의 변이음에는 어두운 [l]과 밝은 [l]이 있다고 알려져 왔으나 최근 설측음의 변이음의 종류가 언어마다 다르다는 주장이 제기되고 있다. 본 연구에서는 영어 설측음 /l/이 음절 내 출현 위치에 따라 연구개음화의 실현 정도가 유의미하게 다른 변이음이 있는지 확인하기 위해 자연발화 음성 데이터베이스인 벅아이 코퍼스를 이용하였다. 먼저, 설측음의 음절 내 출현 위치에 따라 측정한 포만트 주파수를 비교한 결과 음절 내 모든 위치에서 유의미한 차이를 보이는 F2 주파수를 근거로 연구개음화 정도가 유의미하게 다른 변이음이 어두운 [l]과 밝은 [l] 이외에도 존재한다고 판단할 수 있었다. 또한 인접 모음의 후설성이 설측음의 연구개음화에 미치는 영향으로 인해 표준적인 어두운 [l]과 표준적인 밝은 [l] 이외의 변이음이 존재하는지 확인하기 위해 포만트 주파수를 측정하고 이에 대해 분산분석을 한 결과 음절 말 위치에서 연구개음화될 때에도 인접 모음이 후설모음인 경우 인접 모음이 전설모음인 경우와 비교했을 때 유의미하게 차이나는 F2 주파수를 보여 연구개음화되는 정도에 차이가 있음을 확인할 수 있었다. 이는 음절 초 위치에서 설측음이 실현될 경우에도 마찬가지로 인접 모음의 종류에 무관하게 모든 설측음이 음절 초 위치에서는 표준적인 밝은 [l]로 발음될 것이라고 예측했지만 실제 F2 주파수는 음절 말 위치에서 선행모음이 전설모음일 경우의 설측음과 유사한 결과를 나타냈다. 이를 통해 음절 내의 위치뿐만 아니라 인접 모음의 후설성이 설측음의 연구개음화 정도에 미치는 영향이 매우 크다는 점을 확인할 수 있고, 이러한 논문의 결과는 설측음의 변이음의 종류가 언어마다 다르고 미국 영어의 경우 다양하게 나타난다는 주장에 대한 하나의 음성학적 근거로 사용될 수 있을 것이다.

• The Journal of the Acoustical Society of Korea
• /
• 제24권4E호
• /
• pp.144-151
• /
• 2005

We evaluate the performance of emotion recognition via speech signals when a plain speaker talks to an entertainment robot. For each frame of a speech utterance, we extract the frame-based features: pitch, energy, formant, band energies, mel frequency cepstral coefficients (MFCCs), and velocity/acceleration of pitch and MFCCs. For discriminative classifiers, a fixed-length utterance-based feature vector is computed from the statistics of the frame-based features. Using a speaker-independent database, we evaluate the performance of two promising classifiers: support vector machine (SVM) and hidden Markov model (HMM). For angry/bored/happy/neutral/sad emotion classification, the SVM and HMM classifiers yield $42.3\%\;and\;40.8\%$ accuracy, respectively. We show that the accuracy is significant compared to the performance by foreign human listeners.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 1999년도 가을 학술발표논문집 Vol.26 No.2 (2)
• /
• pp.198-200
• /
• 1999

인간이 발성하는 음성에는 의미에 대한 정보 뿐만 아니라 화자의 성별에 따라 고유한 특성을 가지고 있다. 즉 음성은 고음이 강한 여성음성과 남성음성으로 분류할 수 있다. 그러나, 기존의 HMM을 이용한 음성인식시스템에서는 남성과 여성음성의 이러한 특성이 있음에도 불구하고 이를 고려하지 않고, 하나의 HMM으로 구성하고 있다. 본 논문에서 제시하는 알고리즘으로 실험한 결과 남성과 여성의 포만트 주파수가 100~30Hzck이가 나는 것을 알 수 있었고, 이러한 특성을 고려하여 남성과 여성의 음성을 구별할 수 있는 방법을 제안한다. 또한 남성과 여성음성을 각각 구분하여 GMM을 훈련시킨 후 인식과정에서 입력된 음성의 포만트 특성에 따라 남성음성이면 남성 HMM으로 여성음성이면 여성 HMM으로 인식을 수행함으로써 기존의 인식방법보다 남성음성은 5.2% 여성음성은 4.4% 향상된 결과를 얻었다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 추계종합학술대회 논문집
• /
• pp.1223-1226
• /
• 1998

The pre-emephasis filter as the conventional method emphasizes all components of high frequency that reflects the speaker characteristics. However this filter don't show the auditory characteristics of speaker's speech. In order to emphasize the perceptual characteristics, we propose the speaker recognition system that uses the perceptual weighting as the preprocessor because the Auditory characteristic of human is sensitive to the formant peaks. This filter has the characteristcs that both deemphasizes the low-formants and emphasizes the high formants. As a result of the proposed method, we improve the total recognition rate 1.7% better than the conventional method.

• 음성과학
• /
• 제14권1호
• /
• pp.93-103
• /
• 2007

The aims of this study were to examine the acoustic features of Korean and Japanese vowels, and to determine whether new phones that do not have counterparts in Japanese or similar phones that have counterparts improve more from learning. This study consisted of three parts. In Experiment I, a speech production test was performed to observe the acoustic features of Korean and Japanese vowels. In Experiment II, the speech production of Korean vowels produced by Koreans, advanced Japanese learners of Korean, and beginning Japanese learners of Korean was investigated. In Experiment III, a speech perception study of Korean vowels produced by the two Japanese learner groups was conducted to observe the effect of learning on acquiring L2 phones. The conclusion drawn from the study was that the similar phones produced by Japanese show more similarity with those of Koreans than new phones in terms of F1 and F2, but Japanese learners of Korean displayed more improvement in new phones from learning.

• 음성과학
• /
• 제7권2호
• /
• pp.127-137
• /
• 2000

This paper presents a macro script to analyze numeric sounds by a speech analysis shareware, Praat, and analyzes those sounds produced by three students who were born and raised in Pusan. Recording was done in a quiet office. To make a meaningful comparison, dynamic time points in relation to the total duration of voicing segments were determined to measure acoustical values. Results showed that a strong correlation coefficient was found between the repetitive production of numeric sounds within and across the speakers. Very high coefficients among diphthongal numbers (0 and 6) which usually show wide formant variation were noticed. This supports that each speaker produced numbers quite coherently. Also, the frequency differences between the three subjects were within a perceptually similar range. To identify a speaker among others may require to find subtle individual differences within this range. Perceptual experiments by synthesized numeric sounds may lead to resolve the issue.

• 말소리와 음성과학
• /
• 제7권1호
• /
• pp.11-17
• /
• 2015

This paper deals with the correlation between physical fatigue and speech signals. A treadmill task to increase fatigue and a set of subjective questionnaire for rating tiredness were designed. The results from the questionnaire and the collected bio-signals showed that the designed task imposes physical fatigue. The t-test for two-related-samples between the speech signals and fatigue showed that the parameters statistically significant to fatigue are fundamental frequency, first and second formant frequencies, long term average spectral slope, smoothed pitch perturbation quotient, relative average perturbation, pitch perturbation quotient, cepstral peak prominence, and harmonics to noise ratio. According to the experimental results, it is shown that mouth is opened small and voice is changed to be breathy as the physical fatigue accumulates.

• 대한음성학회:학술대회논문집
• /
• 대한음성학회 2007년도 한국음성과학회 공동학술대회 발표논문집
• /
• pp.64-66
• /
• 2007

The purpose of this study was to compare and analyze some acoustic parameters of the cochlear implanted children(N=20, aged 3-10) and to suggest a basic data on speech rehabilitaion for the cochlear implanted children. Acoustic analyses of seven Korean monophthongs produced by 4 contexts(V, CV, VC, CVC) were conducted for the cochler implanted children and normal hearing children(N=20, aged 3-10). Subjects were asked to pronounce a list of vowel repeating three times. The results of this study are the same as follows: First, in the case of the cochlear implanted group, there were no significant differences in F1 and F2. Second, in the case of the normal hearing group, there were significant differences in F2 /ㅜ/ between V and CVC, between VC and CVC. Third, there were significant differences in F1, F2 between CI group and normal hearing group.

• 대한인간공학회지
• /
• 제10권1호
• /
• pp.3-10
• /
• 1991

The teach pendant and keyboard have been used as an input device of control command in human-robot sustem. But, many problems occur in case that the usef is a novice. So, speech recognition system is required to communicate between a human and the robot. In this study, Korean voice commands, eitht robot commands, and ten digits based on the broad phonetic analysis are described. Applying broad phonetic analysis, phonemes of voice commands are divided into phoneme groups, such as plosive, fricative, affricative, nasal, and glide sound, having similar features. And then, the feature parameters and their ranges to detect phoneme groups are found by minimax method. Classification rules are consisted of combination of the feature parameters, such as zero corssing rate(ZCR), log engery(LE), up and down(UD), formant frequency, and their ranges. Voice commands were recognized by the classification rules. The recognition rate was over 90 percent in this experiment. Also, this experiment showed that the recognition rate about digits was better than that about robot commands.

• 대한음성학회:학술대회논문집
• /
• 대한음성학회 2006년도 춘계 학술대회 발표논문집
• /
• pp.63-66
• /
• 2006

This present study investigates the vowels in Bahasa Malaysia and Bahasa Indonesia in terms of the first two formant frequencies. For this study, we recruited 30 male native speakers of Bahasa Malaysia and Bahasa Indonesia (15 each) which include 6 vowels (i, e, a, o, u, a) in various contexts. The present study provides a three-dimensional vowel space by plotting F1, F2, and the frequency of datapoints. This study is significant in that the geophysics of vowel space presents yet another view of the vowel space.