• MALSORI
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• no.59
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• pp.1-11
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• 2006

This study was designed to investigate the relationship between intelligibility and phonemic contrasts, and acoustic features in terms of speech development. A total of 212 Putonghua speaking children was participated in the experiment. There were phonemic contrasts significantly related with speech intelligibility: aspirated vs. fricative, retroflex vs. unretroflex, and front vs. back nasal vowel contrast. A regression analysis showed that 88% of the speech intelligibility could be predicted by these phonemic contrasts. Acoustic values were significantly related to the intelligibility of the Putonghua-speaking children's speech: voice onset time of unaspirated stops, and the duration of frication noise in fricatives.

• Journal of the Ergonomics Society of Korea
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• v.10 no.1
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• pp.3-10
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• 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.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.399-403
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• 1996

This paper addresses issues of perceptual constancy in speech perception through the use of a spatial metaphor for speech sound identity as opposed to a more conventional characterisation with multiple interacting acoustic cues. This spatial representation leads to a correlation between phonetic, acoustic and auditory analyses of speech sounds which can serve as the basis for a model of speech perception based on the general auditory characteristics of sounds. The correlations between the phonetic, perceptual and auditory spaces of the set of English voiceless fricatives /f $\theta$ s $\int$ h / are investigated. The results show that the perception of fricative segments may be explained in terms of 2-dimensional auditory space in which each segment occupies a region. The dimensions of the space were found to be the frequency of the main spectral peak and the 'peakiness' of spectra. These results support the view that perception of a segment is based on its occupancy of a multi-dimensional parameter space. In this way, final perceptual decisions on segments can be postponed until higher level constraints can also be met.

• Journal of Biomedical Engineering Research
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• v.11 no.2
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• pp.283-288
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• 1990

As one of the main purpose of the physical management of cleft palate is to provide for the anatomic and physiologic requisites for speech, the speech must be as one of the criteria for determining when physical management has been achieved. But there is no objective methods to evaluate the speech of cleft palate patients. The authors tried to analyze the speech of adult cleft palate patients using sound spectrog raphy and compared with normal adults. The results were obtained as follows ; 1. In Vowels, cleft palate patients of both sexes showed reduction of frequency of the first and second formant as compared to normal. There was minimal difference in front vowels (i, e, ae) 2. In consonants, cleft palate patients showed reduction of frequency of the first formant in both sexes but reduction of frequency of the second formant was noticed only in fe- male patients. 3. There was no statistical difference in sound spectrograph between plosive, fricative, africative, nasal, and glide consonants.

• Proceedings of the KSLP Conference
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• 2003.11a
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• pp.147-147
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• 2003

Recent aerodynamic and acoustic studies of VPI(velopharyngeal insufficiency) are non-invasive and safety, therefore, many researchers have used it to diagnose the hyper/hyponasality and articulation disorders of cleft palate patients. The purpose of this study was to estimate mainly the oropharyngeal air pressure and over all air flow in cleft lip and palate patients. The pressure-collecting catheter was positioned in the oropharyngel cavity around tongue base. Twelve adult control group and three cleft lip & palate patients were participated to this experimentation. Aerophone II was used to measure peak air flow, mean air flow, phonatory airflow, phonatory efficiency and resistance. The results were as follows: 1) Airflow of cleft lip ＆ palate patients group were higher than those of control group. Fricative sounds /s/ and /s'/ showed the statistic significance of mean airflow and volume data. 2) Intraoral air pressure of cleft lip ＆ palate patients was lower than those of control group.

• Speech Sciences
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• v.10 no.1
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• pp.3-13
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• 2003

The devoicing vowel is a phonological process whose contrast in sonority is lost or reduces in a particular phonetic environment. Phonetically, the vocal fold vibration originates from the abduction/adduction of the glottis in relation to supraglottal articulatory movements. The purpose of this study is to investigate Korean vowel devoicing by means of experimental instruments. The interrelated laryngeal adjustments and aerodynamic effects for this voicing can clarify the redundant articulatory gestures relevant to the distinctive feature of sonority. Five test words were selected, being composed of the high vowel /i/, between the fricative and strong aspirated or lenis affricated consonants. The subjects uttered the test words successively at a normal or at a faster speed. The EMG, the sensing tube Gaeltec S7b and the High-Speech Analysis system and MSL II were used in these studies. Acoustically, three different types of speech waveforms and spectrograms were classified, based on the voicing variation. The intraoral air pressure curves showed differences, depending on the voicing variations. The activity patterns of the PCA and the CT for devoicing vowels appeared differently from those showing the partially devoicing vowels and the voicing vowels.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.93-100
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• 2010

The purpose of this study was to compare the acoustic properties of fricatives, /ㅅ, ㅆ/ produced by children with functional articulation disorder and normal children (N=20, aged 6-7). All subjects showed significant differences in both the length of friction intervals and breathing intervals of fricatives according to the changes in the environment presented within each group. However, there is a difference in the extent of variation in length between the two groups. This means that children with functional articulation disorder have greater difficulty in adjusting fricative noises according to changes in the CV VCV environment than normal children.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.67-74
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• 2010

The purpose of this study was to explore the cross-linguistic difference in the spectral movement pattern of American English and Korean vowels. Eight American vowels /a/, /e/, /$\varepsilon$/, /i/, /I/, /o/, /u/, and /$\mho$/, and five Korean vowels, /a/, /e/, /i/, /o/ and /u/ in a fricative-vowel environment produced by adult speakers of each language were analyzed. The spectral movement patterns of the first two formant frequency values were measured and analyzed. The results showed that Korean vowels had minimal spectral movement, both in F1 and F2 values, as compared to American English vowels. Moreover, no consistent direction of movement was found in the three corner Korean vowels, while American English vowels showed consistent direction of movement for each vowel of the same phonemic category.

• Proceedings of the KSPS conference
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• 2003.05a
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• pp.101-104
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• 2003

The purpose of this study was to compare acoustic differences of fricative /s/ between the dysarthric subjects and normal subjects. In additional, the subjects' speeches were evaluated in terms of word intelligibility containing /s/ and perceptual severity. Acoustic parameters were duration, peak frequency and intensity of /s/. The results showed that the first peak frequency and intensity of /s/ were significantly different between dysarthric subjetcts and normal subjects. Second, peceptual parameters were significantly different between dysarthric subjetcts and normal subjects. The Pearson correlation coefficient was used to determine the relationship between the acoustical and perceptual data. The results showed that there was a strong correlation between perceptual parameters and peak frequency of /s/.

• Phonetics and Speech Sciences
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• v.14 no.2
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• pp.67-76
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• 2022

This study aimed to examine Korean listeners' mode of perceiving sound duration as prolongation, whether dichotomous or continuous. Thirty-five Korean participants (17 men and 18 women) listened to the Korean segment /s/, which was lengthened by 0-980ms in 20-ms increments. Then, the participants were asked to rate each version of the sound based on a rating of one to 100 (the closer to 100, the more disfluent). To examine whether listeners perceived durational variations for the fricative segment dichotomously or continuously, a curve was estimated using the best-fitting regression model for the observed data with the highest adjusted R-squared value. The mode of perceiving durational variations for the segment was continuous (or gradient) rather than discontinuous (or dichotomous). No gender difference was found in the mode of perceiving prolongation. However, there was a significant gender difference in that men rated the most disfluent sounds higher than women. The findings of this study were further discussed in relation to the existing literature, and clinical implications for the assessment of stuttering were presented.