The purpose of the present study is to test whether VOT values of the Korean plain stops in intervocalic position are encoded differently by individual speakers. In Scobbie (2006), the VOT values to the /p/-/b/ voicing contrast in Shetland Isles English were found to demonstrate a high degree of inter-speaker variation. More importantly such variation was not arbitrary: first, there was an inverse relationship between the amount of prevoicing for /b/ and the duration of aspiration for /p/. Second, the inter-speaker variation was shown to be similar between the subjects and their parents. These results suggest that the phonetic targets for VOT are specified in fine detail by speakers. The present study further explores this issue in terms of testing 1) whether the likelihood and the amount of voicing for the intervocalic plain stops in Korean show inter-speaker variation; 2) whether the likelihood and the exact amount of voicing for the intervocalic plain stops in Korean are closely related to the amount of aspiration for the Korean intervocalic aspirated stops. The results of the study suggest that the voicing of intervocalic plain stops in Korean varied according to the individual speakers, but it did not seem to be directly interrelated with the amount of aspiration of the aspirated stop sin the same phonological position.

Several studies on the pronunciation of English vowels point out that Korean learners have difficulty distinguishing English tense and lax vowel pairs. The acoustic comparisons of those studies are mostly based on the formant measurement at one time point of a given vowel section. However, the English lax vowels usually show dynamic changes across their syllable peaks and subjects' English levels account for various conflicting results. The purposes of this paper are to compare the temporal duration and dynamic formant tracks of English tense and lax vowel pairs produced by five Korean and five American males. The subjects were graduate students of an American state university. Results showed that both the Korean and American males produced the vowels with comparable durations. The duration of the front tense-lax vowel pair was longer than that of the back vowel pair. From the formant track comparisons, the American males produced the tense and lax pairs much more distinctly than the Korean male speakers. The results suggest that the Korean males should pay attention to the F1 and F2 movements, i.e., the jaw and tongue movements, in order to match those of the American males. Further studies are recommended on the auditorily acceptable ranges of F2 variation for the lax vowels.

The purpose of this paper is to examine how Chinese speakers realize Korean prosodic phrases in the reading of Korean texts. Prosodic phrase, in this study, is defined as basic unit of spoken language which can be perceived as purely separate phonetic unit by both hearer and speaker, and is realized with a coherent intonational configuration. Prosodic phrase plays an important role in both speech production and perception. In the second language acquisition, prosody influences the accuracy and fluency of spoken language. The main purpose of this study is to describe the aspect of syntagmatic operation of prosody that produces prosodic phrases. We have specifically examined the relations between the prosodic phrase's boundary and its syntactic status. Furthermore, we examined internal syntactic structure of each prosodic phrase. And the results of each analysis were compared to the aspects of prosodic phrases' formation produced by native Korean speakers. The results show that Chinese speakers tend to coincide the prosodic phrases with syntactic structure more than native Korean speakers.

Instrumental studies (e.g., aerodynamic, EPG, and EMMA) have shown that the first of two stops in sequence can be articulatorily reduced in time and space sometimes; either gradient or categorical. The current EMMA study aims to examine possible factors_linguistic (e.g., speech rate, word boundary, and prosodic boundary) and paralinguistic (e.g., natural context and repetition)_to induce gradient reduction of $C_1$ in /pk/ cluster sequences. EMMA data are collected from five Seoul-Korean speakers. The results show that gradient reduction of lip aperture seldom occurs, being quite restricted both in speaker frequency and in token frequency. The results also suggest that the place assimilation is not a lexical process, implying that speakers have not fully developed this process to be phonologized in the abstract level.

The accuracy rate of P2G (Phoneme-to-Grapheme) is one of the important factors determining the quality of unlimited voice recognition (VR) systems. Few studies were, however, conducted to reduce ambiguities of a phoneme string which can be segmented into a variety of different linguistic units (i.e. morphemes, words, eo-jeols), thus be transformed into more than one grapheme string. This paper is a preliminary research for building a large knowledge base of those homonymic & heterographic units(HHUs), which will provide unlimited Korean VR systems with more accurate P2G information. This paper analyzes 2 main factors generating HHUs: (1) boundary determination of the prosodic unit; (2) its segmentation into linguistic units. In this paper, linguistic characteristics determining variable boundaries of a prosodic unit are investigated, and the ambiguity types of HHUs are classified in accordance with their morphological and syntactic structures as well as with the phonological rules governing them.

Automatic speech recognition has severe performance degradation under noisy environments. To cope with the noise problem, many methods have been proposed. Most of them focused on noise-robust features or model adaptation. However, researchers have overlooked utterance verification (UV) under noisy environments. In this paper we discuss UV problems based on the normalized confidence measure. First, we show that UV performance is also degraded in noisy environments with the experiments of an isolated word recognition. Then we observe how the degradation of UV performances is suffered. Based on the UV experiments we propose a modeling method of the statistics of phone confidences using sigmoid functions. For obtaining the parameters of the sigmoidal models, the particle swarm optimization (PSO) is adopted. The proposed method improves 20% rejection performance. Our experimental results show that the PSO-NCM can apply noise speech recognition successfully.

Nowadays an HMM-based text-to-speech system (HTS) has been very widely studied because it needs less memory and low computation complexity and is suitable for embedded systems in comparison with a corpus-based unit concatenation text-to-speech one. It also has the advantage that voice characteristics and the speaking rate of the synthetic speech can be converted easily by modifying HMM parameters appropriately. We implemented an HMM-based Korean text-to-speech system using a small size Korean speech DB and proposes a method to increase the naturalness of the synthetic speech by controlling duration model parameters in the HMM-based Korean text-to speech system. We performed a paired comparison test to verify that theses techniques are effective. The test result with the preference scores of 73.8% has shown the improvement of the naturalness of the synthetic speech through controlling the duration model parameters.

This paper intends to investigate the correlation of 12 MDVP measurements with age, sex and body-size of sampled healthy patients. In order to extract pitch and 12 MDVP parameters efficiently and display the correlation of each parameter easily, we developed the speech analysis program using C/C++ and MFC development tool. The sample group consists of 205 males and 343 females with ages 9-81. We collected vowel voices /a/ and 8 body-size measurements from them. Body-size values were taken at 8 different torso positions of each person. We analyzed the matched voice samples and body-size measurements by the developed speech analysis program and SPSS program. The result shows that a typical characteristic age-F0 pattern that F0 of male subjects are rapidly decreased after mutational period and have stable state with age and that of female subjects are slowly changed by overall age. In MDVP, age-STD in males, age-sPPQ in females relationships are especially similar to the age-F0 relationship. In case of male group, sPPQ(0.316%), Jitt(0.04%), Shim(0.25%), APQ(0.28%) variables are increased with age after mutational period. And Jitt(0.042%), sPPQ(0.219%) of females group are increased with age too. In cases of height, weight and BMI there exists a weak correlation with MDVP, which shows a correlation coefficient below 0.25 about male and female groups. The survey of correlation relationship between 8 body-size measurements and MDVP shows a insignificant statistical result by only just having the correlation coefficient maximum in M8-8 and F0(-0.394%) for males and M8-6,7(-0.368%, -0.364%) for females.

This paper proposes the way of improvement and system build-up for shop music broadcasting services provided by the Internet. Comparing the shop music broadcasting services and personal music broadcasting services, we propose the way of shop music broadcasting services customers prefer to. That is, such a function is provided that a user can control the broadcasting music lists a specialist provides according to the current circumstance of shop. This paper proposes the whole system such a service is possible and verifies the efficiency by experiments.

Breath group generally refers to one of units of speech production. It is an integral component of structural and contextual features of utterances with some responsibility for fluctuations in speech intelligibility. The purpose of this study was to know the characteristics of breath group in reading passages spoken by healthy speakers, specifically in view of aerodynamic aspects. Eighteen female speakers aged from 20 to 30 years old without communication problems and in healthy condition were participated in this study. PAS (Phonatory Aerodynamic System) was used for aerodynamic measurement of breath group. Results showed that the mean value of breath group in reading tasks was 16.03 per minute (SD=3.1), and the spoken syllables per one breath group were 17.95. And the mean time (m) of breath group was 3.06 (SD=0.62), and the ratio of exhalation and inhalation was appeared in the 1:5. The results need to be discussed in values of normality of breath group and clinical viewpoint, especially their potential implication from speech intelligibility caused by brain damage.

Habitual speaking fundamental frequency (sF0) plays an important role in determining the voice classification, which can be presented differently depending on the vocal fold length and language habits. The purpose of this study, therefore, was to compare the differences in sF0 for voice classification and closed quotient between speaking and singing. Seventeen singers (7 sopranos, 5 tenors, 5 baritones, mean age 25.1 years) with no evidence of vocal folds pathology were participated. sF0 and closed quotient (CQ) both in speaking and in singing (A3-A5 with soprano, A2-A4 with tenor and baritone) were measured using SPEAD program and electroglottography. No significant differences were observed for sF0 between tenor and baritone groups (p> 0.05). However, CQ in singing was significantly different among three groups (p< 0.05), but CQ in speaking was not (p> 0.05). Furthermore, CQ was significantly different with both soprano (p< 0.01) and tenor groups ((P= 0.02) whereas baritone group revealed there is no difference when compared between speaking and singing. No significant differences in sF0 between tenor and baritone participants may result from decision-making for voice classification by experience and should measure sF0 before determining the voice classification.

The purpose of this study was to find out the ability of coordination of the articulatory motor and the ability of control of the respiration and laryngeal for spastic dysarthria by acoustic analysis. The sustained of vowel /a/ and repetition of syllable /pa/ in 15 normal and 10 spastic dysarthria were measured. Multi-Speech, MDVP, and MSP were used for data recording and analysis. As a result, the mean DDK rate in the spastic group was significantly slower than in the normal. The maximum phonation time in the spastic group ($4.80{\pm}1.94$) was shorter than in the normal ($11.20{\pm}3.72$). The DDKjit in the spastic group was significantly higher than in the normal. The DDKsla was reduced in the spastic group. The mean syllable duration in the spastic group (146.2ms) was significantly longer than in the normal (75.8ms). The mean energy was reduced in the spastic group. The range of Fo was greater than in the normal. The frequency perturbation (jitter, vFo) and amplitude perturbation (shimmer, vAm) were higher than in the normal group. The NHR was higher than in the normal group. The parameters of this were significantly difference between the spastic dysarthria and the normal (p<0.05). Finally, the spastic dysarthria has short respiration, slow speech rate, and voice quality problem. The these results will help to establish a plan and the intervention of treatment.

This study was purposed to introduce Korean Oro-motor Mechanism Screening Examination (KOMSE) and to provide the standardized scores taken from 120 normal adults aged $18{\sim}59$. KOMSE was composed of 13 items of structure, 17 items of function, 3 items of voice, and 14 items of regularity and accuracy of articulation during diadochokinesis. Additionally, maximum phonation time and diadochokinetic rates were measured. Total score of KOMSE is ranged from 0 to 200. It was significantly higher in the $50{\sim}59$ age group than in the $20{\sim}29$ age group, but was not significantly different in sex. MPT had a significant difference in sex, but no significant difference among different age groups. The rate of DDK was also had no significant difference among different age groups. However, some reducing trend in the rate of DDK was observed as age increased. KOMSE would be very helpful for SLPs to screen the abnormality of oro-motor mechanism.

In the process of speech therapy, fluency is acquired and speech rate increases in the process when the behavioral modification strategy, inducing speech fluency by making speech rate slower intentionally in an early stage, is applied. Therefore, the purpose of this study was to investigate the pause characteristics in slowed speech intentionally of treated stutterer. In this study, 10 developmental stutterers who had well established fluency in speech were involved. We had collected each 200 syllables sample of intentionally much slowed speech and a little slowed one in reading task. To measure the features of pause, total frequency of pauses, total durations of pauses, average duration of pauses and proportions of pause were investigated. The findings were as follows: Both the total durations and total frequency of pauses of much slowed speech were higher than that of a little slowed one. However, both the average duration and proportions of pauses of much slowed speech were not significantly higher than that of a little slowed one.