• Speech Sciences
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• v.8 no.4
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• pp.139-156
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• 2001

Speech intelligibility in patients with complete dentures is an important clinical problem depending on the material used. The objective of this study was to investigate the speech of two edentulous subjects fitted with a complete maxillary prosthesis made of two different palatal materials: chrome-cobalt alloy and acrylic resin. Three patients with complete dentures in the experiment group and ten people in the controls groups participated in the experiment. CSL, Visi-Pitch were used to measure speech characteristics. The test words consisted of a simple vowel /e/, meaningless three syllabic words containing fricative, affricated and stops sounds, and sustained fricative sounds /s/ and /$\int$/. The analysis speech parameters were vowel and lateral formants, VOT, sound durations, sound pressure level and fricative frequency. Data analysis was conducted by a series of paired T-test. The findings like the following: (1) Vowel formant one of patients with complete denture is higher than that of the control group (p<0.05), while lateral formant three of patients with complete denture is lower than that of the control group (p<0.0l). (2) Patients with complete denture produced lower speech intelligibility with low fricative frequency (/$\int$/) than control group (p<0.0). The speech intelligibility of patients with metal prosthesis was higher than that of those with resin prosthesis (p<0.05). (3) Fricative, lateral and stop sound durations of patients with complete denture were longer than those of the control group (p<0.01 and p<0.05), respectively. Total sound durations of patients with metal prosthesis were similar to that of the control group (p<0.05), while those with resin prosthesis had a shorter duration (p<0.01). This implied that those with metal prosthesis had higher speech intelligibility than those with resin prosthesis. (4) Patients with complete denture had higher sound pressure levels /t/ and /c/ than the control group (p<0.01). However, sound pressure levels for /c/ of patients with metal prosthesis or resin prosthesis was similar to the control group (p<0.05). (5) Patients with complete denture had higher fundamental frequency than the control group (p<0.01).

• Phonetics and Speech Sciences
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• v.5 no.1
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• pp.73-80
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• 2013

Formant is one of the essential vocal features for research of voice production, recognition and synthesis. Numerous studies were established on foreign languages including English vowels. However, studies related to Korean were done with a limited number of voice data. In this study, we compare four formants according to age and gender using a large number of Korean monophthongs. A total of 2614 Korean speakers participated in our experiments. We summarize statistical results by mean and standard deviation for each formant of five monophthongs. The results show a notable difference in each age and gender group. A quantitative study based on a large dataset is suggested for future studies on Korean speech sounds.

• Speech Sciences
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• v.14 no.4
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• pp.221-232
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• 2007

Topiramate (TPM) is a new antiepileptic drug characterized by a clinical effective reduction in seizure frequency and it represents a useful drug effective in a wide range of epileptic patients. Known side effects are represented by weight loss, hypohidrosis, anorexia, sedation, nephrolithiasis, cognitive complaints and language disorders. This study is to examine acoustic characteristics of patients with TPM. 15 patients were assessed through a Computerized Speech Lab (CSL) applied before the beginning of therapy with TPM and 3 months after medication had been stabilized. Tests had been chosen to assess voice onset time (VOT), total duration (TD), vowel formants, loudness, pitch, speaking rate, and articulation patterns. We compared the data from patients and healthy volunteers. The statistical analysis of the results did not show changes in acoustic tests, except for TD which was increased. The increase of the TD is evaluated as a deterioration of fluency. Our results suggest that patients with TPM did not experience acoustic speech changes except that fluency was declined. Unlike previous studies, the medication of TPM has nothing to do with speech problems in patients with epilepsy.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.367-371
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• 1996

Most Koreans agree that Korean traditional singing voice has a very peculiar sound comparing to Western singing voice. The goal of this paper is to investigate the acoustic characteristics of Korean traditional singing voice called 'Pansori' Materials are analyzed from 3male professional singers and 4 female professional singers. Their singing was compared with their own conversation and other non-singers' conversation. Long term average spectra indicated that all the singers showed a much less spectral tilt than non-singers. The phenomenon was prevailing for professional singers not only in their singing, but also in their conversation. This suggests that it is not the result of a temporary effort but it may involve a certain permanent change in their physiological configuration. (To assess this hypothesis, voice source should be looked at directly. Therefore, in further research, using Rothenberg mask (Rothenberg, 1973) is strongly recommended.) In addition to LTA, individual vowel formants will be studied later.

• Phonetics and Speech Sciences
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• v.2 no.1
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• pp.51-58
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• 2010

This study investigates the perception and production of English front vowels focusing on the distinction in /i/ vs /I/ and /$\varepsilon$/ vs /$\ae$/ by sixty-one Korean speakers. The first portion of this study focused on the perceptional discrimination by the subjects of two sets of English vowel contrasts, /i/ vs /I/ and /$\varepsilon$/ vs /$\ae$/. In the second portion of the study, the production of these vowels by the same subjects who had participated in the perceptional discrimination test was examined acoustically and subsequently compared with that of the control group comprised of native English speakers. The major results indicate that: (1) In perception tests, Korean subjects can discriminate between /i/ and /I/ relatively well, while many of them were not able to discriminate between /$\varepsilon$/ and /$\ae$/; (2) the Korean subjects, however, have difficulty producing a distinct version of these front vowels; and, (3) The relationship between the perception and production is not significant. These results were analyzed with the concept of "under-differentiation" and "reinterpretation of distinction," as well as how phonetic differences influenced the production and discrimination of front vowels by Korean speakers.

• Phonetics and Speech Sciences
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• v.4 no.1
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• pp.29-47
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• 2012

The purpose of this paper is to show how to convert the label files of the Buckeye Corpus of Spontaneous Speech [1] into Praat format and to introduce some of the Praat scripts that will enable linguists to study various aspects of spoken American English present in the corpus. During the conversion process, several types of errors were identified and corrected either manually or automatically by the use of scripts. The Praat script tools that have been developed can help extract from the corpus massive amounts of phonetic measures such as the VOT of plosives, the formants of vowels, word frequency information and speech rates that span several consecutive words. The script tools can extract additional information concerning the phonetic environment of the target words or allophones.

• Speech Sciences
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• v.14 no.2
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• pp.65-71
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• 2007

The severe-profound hearing impaired children have various disorders in everday communication due to the lack of hearing feedback. Especially, their speech produced unstable voice, omission and distortion of articulation, pitch break, cul-de-sac voice, and so on so that they were difficult to accurately deliver an intended message. This study attempts to analyze the acoustic characteristics of 4 vowel sounds produced by 35 severe-profound hearing impaired children using CSL(Computerized Speech Lab, Model 4300b). The formant data were obtained from the spectrogram and analyzed data by 12 formant filter and auto-correlation among the formants. Results showed that the hearing impaired children's formant values came out very high. They produced the vowels at the mode of hypertension with unstable voice. In order to improve their speech, they would need some adequate auditory feedback.

• The Journal of the Korea Contents Association
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• v.10 no.6
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• pp.373-377
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• 2010

Numerous quantitative and qualitative studies have already been published related to English vowels. However, only minimal amounts of studies based on the acoustic analysis of Korean vowels have been accomplished. The purpose of this study is to obtain sufficient quantitative data based on the acoustic aspects of Korean vowels produced by males between the ages of 20s and 30s. A total of 31 males in their 20s and 30s produced the five fundamental vowels /a, e, i, o, u/ by repeating each of them three times in the standard Korean dialect. Such speech productions were recorded with 'Cool edit' and F1, F2, F3, F4 were extracted through the MATLAB acoustic analysis program. Results indicated that the overall patterns of formants were similar to previous studies, except that the formant levels of F1 and F2 of the vowels produced in this study were generally lower than that in previous studies. Future studies need to focus on obtaining vowel data by considering other factors such as age and other speech materials.

• Clinical and Experimental Pediatrics
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• v.53 no.9
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• pp.834-839
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• 2010

Purpose: This study investigates Korean speech sound development, including articulatory error patterns, among the Japanese-Korean children whose mothers are Japanese immigrants to Korea. Methods: The subjects were 28 Japanese-Korean children with normal development born to Japanese women immigrants who lived in Jeonbuk province, Korea. They were assessed through Computerized Speech Lab 4500. The control group consisted of 15 Korean children who lived in the same area. Results: The values of the voice onset time of consonants /$p^h$/, /t/, /$t^h$/, and/$k^*$/ among the children were prolonged. The children replaced the lenis sounds with aspirated or fortis sounds rather than replacing the fortis sounds with lenis or aspirated sounds, which are typical among Japanese immigrants. The children showed numerous articulatory errors for /c/ and /I/ sounds (similar to Koreans) rather than errors on /p/ sounds, which are more frequent among Japanese immigrants. The vowel formants of the children showed a significantly prolonged vowel /o/ as compared to that of Korean children ($P$<0.05). The Japanese immigrants and their children showed a similar substitution /n/ for /ɧ/ [Japanese immigrants (62.5%) vs Japanese-Korean children (14.3%)], which is rarely seen among Koreans. Conclusion: The findings suggest that Korean speech sound development among Japanese-Korean children is influenced not only by the Korean language environment but also by their maternal language. Therefore, appropriate language education programs may be warranted not only or immigrant women but also for their children.

• The Journal of the Acoustical Society of Korea
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• v.24 no.2E
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• pp.71-76
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• 2005

Compared to normal speech, distant-talking speech is characterized by the acoustic effect due to interfering sound and echoes as well as articulatory changes resulting from the speaker's effort to be more intelligible. In this paper, the acoustic features for distant-talking speech due to the articulatory changes will be analyzed and compared with those of the Lombard effect. In order to examine the effect of different distances and articulatory changes, speech recognition experiments were conducted for normal speech as well as distant-talking speech at different distances using HTK. The speech data used in this study consist of 4500 distant-talking utterances and 4500 normal utterances of 90 speakers (56 males and 34 females). Acoustic features selected for the analysis were duration, formants (F1 and F2), fundamental frequency, total energy and energy distribution. The results show that the acoustic-phonetic features for distant-talking speech correspond mostly to those of Lombard speech, in that the main resulting acoustic changes between normal and distant-talking speech are the increase in vowel duration, the shift in first and second formant, the increase in fundamental frequency, the increase in total energy and the shift in energy from low frequency band to middle or high bands.