• Korean Journal of Child Studies
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• v.21 no.1
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• pp.35-44
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• 2000

This study examined the development of phonological awareness of 3-, 5-, and 7-year-old children, 20 subjects at each age level. The 3-year-olds were given 2 phoneme detection tasks and the 5- and 7-year-olds were given 5 phoneme detection tasks. In each task, the children first heard a target syllable together with 2 other syllables and were asked to tell which of the 2 syllables sounded similar to the target. Children were able to detect relatively large segments ($Consonant_1+Vowel$ or $Vowel+Consonant_2$: $C_1V$ or $VC_2$) at the age of 3 and gradually progressed to smaller sound segments(e.g., phonemes). This study indicated the Korean children detect $C_1V$ segments better than $VC_2$ segments and detect the initial consonant better than the middle vowel and the final consonant.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.1
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• pp.33-38
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• 2007

Background and Objectives: It has been suggested that tonsillectomy possibly causes changes of voice because the morphology of the vocal tract is altered. This may cause serious problems for professional voice users. Materials and Method: Subjects were 26 patients. The oral and nasal sound spectrum of oral vowel /a/, /e/ and /i/ were measured before and after tonsillectomy. The formant frequencies and intensities for oral and nasal spectra were compared. The nasality and fundamental frequencies for oral vowel were measured. Results: The first formant frequencies for oral spectra of all vowels were not changed after surgery, but the second formant frequencies were increased significantly after surgery in the vowel /e/ and /i/. The first and second formant intensities for oral spectra were increased significantly after surgery in the all vowels. The first and second formant frequencies for nasal spectra of all vowels were not changed after surgery, but their intensities for nasal spectra were increased after surgery. The nasalities for oral vowel were not changed after surgery. Conclusion : Tonsillectomy appeared to change the spectral features of oral and nasal components of oral vowel, especially spectral intensities.

• Phonetics and Speech Sciences
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• v.10 no.4
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• pp.91-99
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• 2018

Korean stops are currently undergoing a tonogenetic sound change, as found in the Seoul dialect in which a merged VOT of aspirated and lax stops induces F0 to be the primary cue for distinguishing the two stops and the lax stops have lower F0 than the aspirated stops. In tonal languages, low tone is produced with a breathy voice. This study investigated whether there are changes in voice quality with respect to the tonogenetic sound change of Korean stops. Two age groups speaking the Seoul dialect participated in this study: five females and six males born in the 1940s and 1950s and nine females and eight males born in the 1980s and 1990s. This study replicated previous findings of VOT and F0 and further examined H1-H2, H1-A1, and H1-A2 to see how they correlate with the sound change. In the older and younger generations, H1-H2, H1-A1, and H1-A2 were significantly lower after the tense stops than after the aspirated and lax stops, but they were not significantly different after the aspirated and lax stops. However, the younger females exhibited some different results for H1-H2 and H1-A2 than the older generation. In the younger females, the H1-H2 mean was higher after the aspirated stops than it was after the lax stops at the vowel onset, and the H1-H2 difference increased at the vowel midpoint. Although there was an inter-speaker variation in the results of H1-H2 and H1-A1, analyses of individual speakers showed that the H1-H2 and H1-A1 were higher after the lax stops than after the aspirated stops in the younger female speakers. These results indicate that lax stops tend to be breathier than aspirated stops in the younger female speakers. They also indicate that changes in voice quality are on Korean stops with tonal sound change, but are still developing.

• Speech Sciences
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• v.9 no.3
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• pp.87-97
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• 2002

The purpose of this study is to analyze the speech duration in Korean-speaking aphasics. Five patients with nonfluent aphasia (2 with traumatic brain injury and 3 with strokes) and five normal adults participated in this experiment. The mean age in patients with nonfluent aphasia was $45.8\pm2.3$ years and $47.4\pm2.3$ years for the normal adults. The Computerized Speech Lab was used to evaluate the acoustic characteristics of the subjects. Voice onset time, vowel duration, total duration, hold and consonant duration were evaluated for the monosyllabic and the polysyllabic words. The patients with nonfluent aphasia did not show the voicing bar on hold area, however, it was seen in the normal persons in the intervocalic position. Explosion duration of glottalized stops in the intervocalic position was significantly prolonged in nonfluent aphasics in comparison with the normal persons. This suggestes that the laryngeal adjustment is disturbed in these patients. Consonant duration, vowel duration, and total duration of the polysyllabic words were significantly longer in the patients with nonfluent aphasia than those of the normal persons. These results demonstrate the disturbances in controlling articulatory muscles during sound production in patients with nonfluent aphasia. The objective and quantitative analysis based on the acoustic characteristics of nonfluent aphasics, will be very useful in therapeutic planning and on the the effects of speech therapy.

• Speech Sciences
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• v.12 no.3
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• pp.59-77
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• 2005

The aim of the present study is to investigate how the phonemic characteristics influence on the disfluencies of children and adults who stutter. The participants were 10 children(9 boys and 1 girl) and 10 male adults. After having the participants to read out the Paradise-Fluency Assessment(Sim, Shin & Lee, 2004) passages, each of the productions were divided into syllables and words, and then the frequencies and the ratios of their disfluenceis were analyzed according to the specified phonemic features. In terms of the frequency of the disfluency, the participants stuttered more in the words which start with consonant than vowel. But they showed more disfluencies in the words initiated with vowel than consonant when the ratio of each phoneme's presences were considered. There found different tendencies among the phonemic features related with their disfluencies occuring with ralatively high frequency or ratio. It was difficult to find out the exact relationships among the order of the sound acquisition, phonemic complexity, and the disfluencies. To study the exact influence of the phonemic features upon the disfluencies, it comes important to consider the frequency of the stuttering itself together with the ratio of the disfluencies in which the opportunity of the specific sound's presence was considered. To compare the results of the different studies which has similar purposes, it seems important to consider the tasks and the methodologies in depth.

• Speech Sciences
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• v.14 no.1
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• pp.137-147
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• 2007

The purpose of this study was to examine the syllable structures of ten Korean numeric sounds produced by ten students. Each sound was normalized by its maximum intensity value and divided into onset, vowel, and coda sections after finding abrupt or visible changes in energy values or cumulative values of lower spectral energy at each pulse point using four Praat scripts. Then, segmental durations and cumulative intensity values of each syllable were obtained to find a statistical summary of the syllable structure. Intensity values at 100 proportional time points were also collected to compare the ten sounds. Results showed as follows: Firstly, there was not much deviation from the grand average duration and intensity for the majority of the sounds except the two diphthongal sounds on which their boundary points varied among the speakers. Secondly, the onset point for the CV or CVC category sounds and the boundary between the vowel and the nasal or lateral sound were easy to identify, which may be automatically traced later. Thirdly, there seems some tradeoff among the sections maintaining the same total duration per each syllable. Further studies on syllables with various onsets or codas would be desirable to make a general statement on the Korean syllable structure.

• Speech Sciences
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• v.15 no.3
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• pp.39-51
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• 2008

Formant measurements are one of the most important factors to objectively test cross-linguistic differences among vowels produced by speakers of any given languages. However, many speech analysis softwares present erroneous estimates and some researchers use them without any verification procedures. The purposes of this paper are to examine formant measurements of complex waves which were synthesized from the average formant values of five Korean vowels using three default methods in Praat and to verify the measured values of the five vowels produced by 20 students using one of the methods. Variances along the time axis are discussed after determining absolute difference sum from the 1/3 vowel duration point. Results show that there were smaller measurement errors by the burg method. Also, greater errors were observed in the sl or lpc methods mostly caused by the inappropriate formant settings. Formant measurement deviations were greater in those vowels produced by the female students than those of the male students, which were mostly attributed to the settings for the vowels /o, u/. Formant settings can best be corrected by changing the number of formants to the number of visible dark bands on the spectrogram. Those results suggest that researchers should check the validity of the estimates from the speech analysis software. Further studies are recommended on the perception test of the original sound with the synthesized sound by the estimated formant values.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.171-184
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• 2013

This study investigated the devoicing rate of Japanese high vowels, focusing on regional and generational differences by acoustically analyzing vowels from two large speech databases. The first speech database used in this study was collected between 1986 and 1988 from 41 areas (prefectures) which included 607 participants (299 high school students and 308 their grandparents). The second was taken from a 2006-2007 collection from seven areas as a follow-up investigation to the first database consisting of 463 participants ranging in age from 8-90 year olds. The results revealed there is a generational as well as regional difference in the devoicing rate in almost all areas. Based on those results, a new distribution map reflecting a current devoicing rate of the younger generation was presented. Furthermore, by comparing the two data sets, this study confirmed age difference in the devoicing rate is not age-grading but a sound change in progress. This study discusses the social factors for changes in the devoicing rate of some areas and then applies the devoicing rate of five areas to an S-curve model to predict the future devoicing rate.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.1
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• pp.76-80
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• 2000

Tongue-tip trill is a sound made by the tongue tip making contract with the alveolar ridge and oscillating rapidly as sound is produced. It is an exercise used by many singers to warm up the voice and used as one of the methods of voice rehabilitation for patients who have the vocal folds scarred postoperatively and also who present with a variety of disorders, particularly hypofunction and presbyphonia. We intended to investigate the mucosal vibration of the true vocal folds on tongue-tip trill by electroglottography and to find e effective methods of tongue-tip trill. One adult male volunteer participated. Spectrography and electroglottography were checked repeatedly 15 times, more than 5 second in each times, at same pitch, in three conditions of phonation : sustained /a/ vowel, anterior trill in which tongue-tip vibrated at anterior portion of alveolar ridge just behind the anterior tooth, and posterior trill in which at palatal crest behind the transverse palatine fold We measured the first and second formant to determine indirectly the position of tongue and calculated speed quotient and the ratio of closing phase to closed phase. Speed quotients of posterior trill were higher than sustained /a/ vowel and anterior trill in 14 times. The ratio of closing phase to dosed phase of posterior trill were lower than the others in 14 times. Mucosa of true vocal folds is vibrated more effectively on posterior trill rather than sustained /a/ vowel and anterior trill. So, when tongue-tip trill is used as a method of voice rehabilitation, we suggest that posterior trill is better in producing effective mucosal vibration

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.1
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• pp.10-14
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• 2005

Background and Objectives : Vowels are characterized on the basis of formant patterns. The first formant(F1) is determined by high-low placement of the tongue, and the second formant (F2) by front-back placement of the tongue. The fundamental frequency(F0) of a soprano often exceed the normal frequency of the first formant. And the vocal intensity is boosted when F0 is high and a harmonic coincides with a formant. This is called a formant tuning. Experienced singers thus learned how to tune their formants over a resonable range by lowering the tongue to maximize their vocal intensity. So, the current study aimed to identify the formant tuning in one experienced soprano by comparing the first formants of vowel [i] in three different voice production : speech, ascending scale, and vocalize. Materials and Method : All voices recordings of vowel [i] in speech, ascending scale (from F4 note to A4 note), and vocalize(:Ridente la calam") were made with digital audio tape-corder in a sound treated room. And the captured data were analyzed by the long term average(LTA) power spectrum using the FFT algorithm of the Computerized Speech Lab(CSL, Kay elementrics, Model, 4300B). Results : Although the first formant of vowel [i] in speech was 238Hz, those of ascending scale [i] were 377Hz, 405Hz, 453Hz respectively in F4(349z), G4(392Hz), A4(440Hz) note, and 722Hz, 820Hz, 918Hz respectively in F5 (698Hz), G5(784Hz), A5(880Hz) note. In vocalize, first formants of [i] were 380Hz, 398Hz, 453Hz respectively in F4, G4, A4 note, and 720Hz, 821Hz, 890Hz respectively in F5, G5, A5 note. Conclusion : These results showed that the first formant of ascending scale and vocalize sustained higher frequency than fundamental frequency in high pitch. This finding implicates that the formant tuning of vowel [i] in ascending scale was also noted in vocalize.