• Phonetics and Speech Sciences
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• v.1 no.4
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• pp.3-9
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• 2009

Acoustically English vowels are defined primarily by formant values. The measurements of the values have been usually made at a few time points of the vowel segment despite the fact that the majority of English vowel formants vary dynamically throughout the segment. This study attempts to collect acoustic data of the nine English vowels published by Hillenbrand et al. (1995) online and to examine the acoustic features of the English vowels for phoneticians and English teachers. The author used Praat to obtain the data systematically at six equidistant timepoints over the vowel segment. Obvious errors were corrected based on the spectrographic display of each vowel. Results show that the first two formant trajectories are important to separate the nine vowels within the front- or back-vowel groups. The third formant trajectories appear comparable except those of the high vowels. Second, the back vowels leave longer traces on the vowel space toward the locus of the following consonant /d/. Third, each vowel has inherent duration, pitch, and intensity patterns. The results match the findings of Yang (2009). From the results, the author concludes that dynamic spectral changes are important in specifying acoustic characteristics of English vowels. Further studies on the application of the vowel trajectories to English pronunciation lessons or on perceptual experiment of synthesized vowels are desirable.

• Phonetics and Speech Sciences
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• v.5 no.4
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• pp.17-24
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• 2013

This study is aimed at finding out different types of speech characteristics categorized based on voice rehabilitation techniques used on twenty-six patients (all-male) with total or partial laryngectomees. The speech intelligibility of standard esophageal (SE), tracheoesophageal speech (TE), and electriclarynx (EL) was measured by using the CSL and eleven listeners were instructed to rate the speech on a 5-point scale. The vowel space parameters such as vowel space, VAI, FCR, and F2 ratio were measured by averaging 5 repeats of each vowel (/a/, /e/, /i/, /u/) and the results were put into the parameter formula. The results showed significant statistical differences in speech intelligibility and vowel space between SE and TE. The speech intelligibility and vowel space of TE were higher than those of SE or EL and there was a high correlation between speech intelligibility and some parameters (vowel space, VAI, F2 ratio). The results also showed that TE's speech characteristics were most similar to normal groups comparing with SE and EL, but still very deviant in laryngeal speech. This was due to insufficient airflow intake into the esophagus when producing sounds, and because articulation movement was carried out differently among groups. Therefore, these findings will contribute to establishing a baseline related to speech characteristics in voice rehabilitation for patients with alaryngeal speech.

• Phonetics and Speech Sciences
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• v.8 no.3
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• pp.51-59
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• 2016

The purpose of present study is to examine differences between habitual speech (HS) and clear speech (CS) in individuals with mild dysarthria. Twelve speakers with mild dysarthria and twelve healthy control speakers read sentences in two speaking styles. Formant and intensity related values, triangular area, and center of gravity of /a/, /i/, and /u/ were measured. In addition, formant-ratio variables such as vowel space area(VSA), vowel articulatory index (VAI), formant centralization ratio (FCR) and F2i/F1u ratio (F2 ratio) were calculated. The results of repeated-measures ANOVA showed a significant difference in F2 of vowel /i/ and F2 energy of vowel /a/ between groups. Regarding formant energy, F2 energy of vowel /a/ were observed as meaningful variables between speaking styles. There were significant speaking style-by-group interactions for F2 energy of vowel /a/. These findings indicated that current parameters could discriminate healthy group and mild dysarthria group meaningfully and that speaker with dysarthria had larger clear speech benefit than healthy talkers. We also claim that various acoustic changes of clear speech may contribute to improving vowel intelligibility.

• Phonetics and Speech Sciences
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• v.6 no.2
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• pp.89-96
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• 2014

This study measured speech intelligibility in relation to the vowel space area and the perception of the listener through acoustic analysis of children who had received cochlear implants. It also provided basic data in the evaluation of speech intelligibility by analyzing the correlation between the vowel space area and speech intelligibility. As a research method, the vowel space area was analyzed by obtaining the value of $F_1$, $F_2$ in children three years after receiving cochlear implants, and compared them to normal children by measuring speech intelligibility through interval scaling. A product-moment correlation analysis was conducted to investigate the correlation. Results showed that the vowel space area of the children who had received cochlear implants was significantly different from that of the normal children, though their speech intelligibility showed similar points to those of the normal children. The results of the correlation analysis on the vowel space area and speech intelligibility showed no significant correlation. Therefore, the period of improving intelligibility after receiving cochlear implants and the objective standards of the vowel space area could be established. In addition, the acoustic rating was required to increase the accuracy of the objective measurement in the evaluation of speech intelligibility.

• Speech Sciences
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• v.5 no.2
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• pp.131-138
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• 1999

This study was done to investigate the English front vowels /e/ and /${\ae}$/. These vowels are difficult for Koreans to discern and pronounce. So they show a foreign accent in pronouncing them. In order to find out the reason for Koreans' foreign accent, experiments are carried out with the help of acoustic instruments. The results of the experiment show that there is a considerable difference, especially in vowel length, between the way Korean and Americans pronounce the two English vowels, /e/ and /${\ae}$/. When Americans pronounced English front vowel /e/ and /${\ae}$/ there was a big difference in vowel length between the two vowels. But for Koreans there was only a little difference between two vowels and as a result Koreans showed a foreign accent when they spoke these two English front vowels. Therefore we need to consider the difference of vowel lengths between /e/ and /${\ae}$/ in teaching English pronunciation.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.207-207
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• 1996

The neutral tone is one of the most important distinguishing features in Beijing Mandarin, but there are two completely different views on its linguistic function: a special tone(Xu, 1980) versus weak stress(Chao, 1968). In this paper, the acoustic manifestation of the neutral tone will be explored to show that it is closely related to weak stress. 122 disyllabic words in which the second syllable carries the neutral tone, including 22 stress pairs, were uttered by a native male speaker of Beijing dialect and analysed by Kay Digital Sonagraph 5500-1. The results of the acoustic analysis are presented as follows: 1) The first two formants of the medial and the syllabic vowel moves towards that of central vowel with a greater magnitude in the syllable with the neutral tone than in the syllable with any of the four normal tones. Also the vowel ending, and nasal coda /n/ and / / in the syllable with the neutral tone tends to be deleted. 2) In the syllables with the neutral tone, there are strong carryover coarticulations between the medial and syllabic vowel and the preceding unvoiced consonant. In general, the vowel is affected to move towards the position of the central vowel with more greater magnitude by coronal consonant than by labial or velar consonant. 3) In the syllable with the neutral tone, when and only when it precedes a syllable with tone-4, the high vowel following [f], [ts'], [s], [ts'], [s], [tc'] or [c] tends to be voiceless. 4) It can be seen from the acoustical results of 22 stress pairs that the duration of the syllable with the neutral tone is on the average reduced to 55% of that of the syllable with the four normal tones, and the duration of the final in the syllable with neutral tone is on the average reduced to 45% of that of the final in the syllable with the four normal tones(Lin & Yan 1980). 5) The FO contour of the neutral tone is highly dependent on the preceding normal tone(Lin & Yan 1993). For a number of languages it has been found that the vowel space is reduced as the level of stress placed upon the vowel is reduced(Nord 1986). Therefore we reach the conclusion that the syllable with neutral tone is related to weak stress(Lin & Yan 1990). The neutral tone is not a special tone because the preceding normal tone.

• Phonetics and Speech Sciences
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• v.4 no.4
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• pp.29-35
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• 2012

The purpose of this study was to measure the first two vowel formants of the forty male and female speakers (twenty young vs. old male speakers and twenty young vs. old female speakers) from the Buckeye Corpus of Conversational Speech and to examine the vowel formant changes across two generations (younger vs. older). The results indicated that the vowel space of the younger generation (in their thirties or less) shifted to the lower left position compared to those of the older generation (in their forties or more) in both male and female speakers. When the results were compared to those of Peterson & Barney (1952), it appears that differences can be found in the size of the vowel spaces through time.

• Phonetics and Speech Sciences
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• v.10 no.2
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• pp.45-50
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• 2018

The vowel/consonant ratio is a well-known cue for the voicing of postvocalic consonants. This study investigates how this ratio changes as a function of speaking rate. Seven speakers of North American English read sentences containing target monosyllabic words that contrasted in coda voicing at three different speaking rates. Duration measures were taken for the voice onset time (VOT) of the onset consonant, the vowel, and the coda. The results show that the durations of the onset VOT and vowel are longer before voiced codas, and that the durations of all segments increase monotonically as speaking rate decreases. Importantly, the vowel/consonant ratio, a primary acoustic cue for coda voicing, was found to pattern asymmetrically for voiced and voiceless codas; it increases for voiced codas but decreases for voiceless codas with the decrease in speaking rate. This finding suggests that there is no stable ratio in the duration of preconsonantal vowels that is maintained in different speaking styles.

• Speech Sciences
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• v.13 no.3
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• pp.19-33
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• 2006

This study explores whether Russian, known to have a process of syllable-final devoicing, reveals differences in vowel duration as a function of the underlying voicing of the coda stop. This paper also examines whether non-native speakers of Russian and English learn typical L2 values in vowel duration. The results indicate that vowels in Russian have a slightly longer mean duration before a voiced stop than before a voiceless stop (a mean difference of 9.52 ms), but in most cases the differences did not exhibit statistical significance. In English the mean difference was 60.05 ms, and the differences were in most cases statistically significant. All native Russian speakers of English produced larger absolute differences in vowel duration for English than for Russian, and all native English speakers of Russian produced smaller absolute differences for Russian than for English. More experienced learners seemed to achieve more native-like values of vowel duration than less experienced learners did, suggesting that learning occurs gradually as the learners gain more experience with the L2.

• The KIPS Transactions:PartA
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• v.10A no.1
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• pp.1-6
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• 2003

In this paper, we present a new Korean connected digit recognition based on vowel string and number of syllables. There are two steps to reduce digit candidates. The first one is to determine the number and interval of digit. Once the number and interval of digit are determined, the second is to recognize the vowel string in the digit string. The digit candidates according to vowel string are recognized based on CV (consonant vowel), VCCV and VC unit HMM. The proposed method can cope effectively with the coarticulation effects and recognize the connected digit speech very well.