• Phonetics and Speech Sciences
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• v.3 no.4
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• pp.45-53
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• 2011

Flemming and Johnson (2007) claim that there is a fundamental distinction between the mid central vowel [ə] and the high central vowel [?] in that [ə] occurs in an unstressed word-final position while [?] appears elsewhere. Compared to English counterparts, Korean [ə] and [?] are full vowels and they have phonemic contrast. The purpose of this paper is to explore the acoustic quality of two English reduced vowels produced by Korean learners and native speakers of English in terms of their two formant frequencies. Sixteen Korean learners of English and six native speakers of English produced four types of English words and two types of Korean words with different phonological and morphological patterns. The results show that Korean learners of English produced the two reduced vowels of English and their Korean counterparts differently in Korean and English words.

• Korean Journal of English Language and Linguistics
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• v.1 no.2
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• pp.311-329
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• 2001

This paper wanted to test the reality of English schwa by phonetic and phonological methods. Phonetically it wanted to see acoustic evidence of the relationship between the full vowels and their reduced vowels in the unstressed positions. Phonologically it wanted to prove how systematic the schwa sound is by the constraint-based grammar. As a result, the schwa phenomenon in English was supported both phonetically and phonologically. In the phonetic analysis no relationship Was found in the distribution of the F1 and F2 of the full vowels and their reduced vowels in the unstressed syllables of the derived words. The reduced vowels tended to converge into a target of F1 516 and F2 1815. The view that the schwa sounds have a target was supported. On the phonological side the constraint-based tableau produced the successful output by using FAITH (V), (equation omitted)V, FAITH V[-BACK+HiC], V[-Low, -TNS]#, REDUCE V[-STR, -TNS] as constraints. No ranking was found. Any violation of the constraints ousted the candidates.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.198-206
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• 1996

Using eighteen text materials from various goners of present-day Japanese, we collected phonologically reduced forms frequently observed in conversational Japanese, and classified them in search of unified explanation of phonological reduction phenomena. We found 7,516 cases of reduced forms which we divided into 43 categories according to the types of phonological changes they have undergone. The general tendencies ale that deletion and fusion of a phoneme or an entire syllable takes place frequently, resulting in the decrease in the number of syllable. Typical examples frequently observed throughout the materials are : $~/noda/{\rightarrow}~/nda/,{\;}-/teiru/{\rightarrow}~/teru/,{\;}~/dewa/{\rightarrow}~/zja/,{\;}~/tesimau/{\rightarrow}~/cjau/$. From morphosyntactic point of view phonological reduction often occurs at the NP and VP morpheme boundaries. The following findings are drawn from phonological observations of reduction. (1) Vowels are more easily deleted than consonants. (2) Bilabials(/m/, /b/, and /w/ are the most likely candidates for deletion. (3) In a concatenation of vowels, closed vowels are absorbed into open vowels, or two adjacent vowels come to create another vowel, in which case reconstruction of the original sequence is not always predictable. (4) Alveolars are palatalized under the influence of front vowels. (5) Regressive assimilation takes place in a syllable starting with ill, changing the entire syllable into phonological choked sound or a syllabic nasal, depending on the voicing of following phoneme.

• Speech Sciences
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• v.8 no.4
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• pp.229-241
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• 2001

Using eighteen texts from various genera of present-day Japanese, I collected phonologically reduced forms frequently observed in conversational Japanese, and classified them in search of a unified. explanation of phonological phenomena. I found 7,516 cases of reduced forms which I divided into 43 categories according to the types of phonological changes they have undergone. The general tendencies are that deletion and fusion of a phoneme or an entire syllable takes place frequently, resulting in the decrease in the number of syllables. From a morphosyntactic point of view, phonological reduction often occurs at the NP and VP morpheme boundaries. The following findings are drawn from phonetical observations of reduction. (1) Vowels are more easily deleted than consonants. (2) Bilabials ([m], [b], and [w]) are the most likely candidates for deletion. (3) In a concatenation of vowels, closed vowels are absorbed into open vowels, or two adjacent vowels come to create another vowel, in which case reconstruction of the original sequence is not always predictable. (4) Alveolars are palatalized under the influence of front vowels. (5) Regressive assimilation takes place in a syllable starting with [r], changing the entire syllable into a phonological choked sound or a syllabic nasal, depending on the voicing of the following phoneme.

• Speech Sciences
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• v.9 no.4
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• pp.49-58
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• 2002

This study was designed to examine the effects of vocal loudness on Nasalance scores in Korean vowels. One normal adult without 'hypemasality' produced 3 types of vowels (/i/, /a/, /u/) in 3 levels of loudness (60, 70, 80dB). Nasalance scores (%) and oral & nasal energy intensity (dB) were measured through NasalView system. These data were compared among 3 levels of loudness and among 3 types of vowels. The results were as follow: For all vowels, Nasalance scores significantly reduced when vocal loudness increased. Because the increases of oral energy intensity were larger than that of nasal energy intensity. For all levels of loudness, Nasalance scores significantly differed among vowel types (/i/>/a/>/u/).

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.75-83
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• 2012

The aims of this study were three. First, to examine the degree of deviation from dictionary prescribed symbols and actual speech made by American English speakers. Second, to measure the frequency of vowel and consonant production of American English speakers. And third, to investigate gender differences in the segmental sounds in a speech corpus. The Buckeye Speech Corpus was recorded by forty American male and female subjects for one hour per subject. The vowels and consonants in both the phonemic and phonetic transcriptions were extracted from the original files of the corpus and their frequencies were obtained using codes of a free software R. Results were as follows: Firstly, the American English speakers produced a reduced number of vowels and consonants in daily conversation. The reduction rate from the dictionary transcriptions to the actual transcriptions was around 38.2%. Secondly, the American English speakers used more front high and back low vowels while three-fourths of the consonants accounted for stops, fricatives, and nasals. This indicates that the segmental inventory has nonlinear frequency distribution in the speech corpus. Thirdly, the two gender groups produced vowels and consonants similarly even though there were a few noticeable differences in their speech. From these results we propose that English teachers consider pronunciation education reflecting the actual speech sounds and that linguists find a way to establish unmarked segmentals from speech corpora.

• Speech Sciences
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• v.7 no.4
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• pp.93-105
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• 2000

The English schwa sound has special characteristics which are distinct from other vowels. It is non-phonemic and occurs only in an unstressed syllable. Compared with the English schwa, the Korean /e/ is a full vowel which has phonemic contrast. This paper had three aims. One was to see whether there is any relationship between English full vowels and their reduced vowel schwas. Second was to see whether there is any possible target in the English schwa sounds which are derived from different full vowels. The third was to compare the English non-phoneme vowel schwa and the Korean full vowel /e/ in terms of articulatory positions and duration. The study results showed that there is no relationship between each of the full vowels and its schwa. The schwa tended to converge into a possible target which was F1 456 and F2 1560. The Korean vowel /e/ seemed to have its distinct position speaker-individual which is different from the neutral tongue position. The evidence that the Korean /e/ is a back vowel was supported by the Seoul dialect speaker. In duration, the English schwa was much shorter than the full vowels, but there was no significant difference in length between the Korean /e/ and other Korean vowels.

• Proceedings of the Acoustical Society of Korea Conference
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• 1996.10a
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• pp.70-75
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• 1996

In this paper, the pre-precessing method for the recognition of single vowels by use of spectrum envelope is presented , we use new method of an extrating spectrum envelope using the diffusion filter bank. We reduced the total processing time, and got higher enhancement of discrimination . By getting 88.3% of average recognition rate for single vowels of real voice through computer simulation, we confirmed it to be useful for speech recongition which use spectrum analysis for voice signal to have many frequency components.

• The Journal of the Acoustical Society of Korea
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• v.16 no.1
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• pp.81-87
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• 1997

In this paper, a new pre-processing method for the recognition of single vowels by use of spectrum envelope is presented. We use new extraction method of a spectrum envelope using the diffusion filter bank. By dividing analysis band of a diffusion filter bank into subbands, we decreased the number of diffusion process. And, by increasing the number of difference, we got higher selectivity. As a result of them, we reduced the total processing time, and got higher enhancement of discrimination. By getting 88.3% of average recognition rate for single vowels of natural voice through computer simulation. We confirmed it to be useful for speech recognition which use spectrum analysis of the voice signal to have many frequency components.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.71-94
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• 1987

This study was carried out to investigate the sound distortion following the alternation of the palatal plate thickness. For this study, 2 healthy male subjects (24-year-old) were selected. Born in Seoul, they both spoke Seoul dialect. First, their sounds of /na(나)/, /da(다)/, /1a(라)/, /ja(자)/, /cha(차)/, /ta(타)/, without inserting plates were recorded, and then the sounds with palatal plates of different thickness were recorded, successively. The plate was fabricated in 3 types, each palatal thickness being 1.0mm, 2.5mm, dentoalveolar portion 2.5mm, other residual portion was 1.0mm, successively. Each type plates named B, C, D-type, in succession. Series of analysis were administered through Computer(16 bit) to analyze the sound distortions. These experiments were analyzed by the LPC (without weighting, pre-weighting, post-weighting) of the consonants, vowels portion, formant frequency of the vowels and word duration of the consonants. The findings led to the following conclusions: 1. There was no correlation of the distortion rate on the 2 informants. 2. Generally, vowels were not affected by the palatal plate thickness in the formant analysis, however, more distortion was detected in the LPC analysis, especially C, D-type plates. 3. Consonants distortion was more evident in the C, D-type plate. 4. The second formant was most disturbed and reduced in the all consonants with insertion of the palatal plate, especially C, D-type plate. 5. Word duration was shortened in the plate inserted(except /ja/, /cha/), especially C, D-type. 6. It was found that dentoalveolar, hard palatal sounds were severely distorted in plate inserted, and they were mainly affected by the dentoalveolar portion thickness. 7. There was correlation between palatal thickness and consonants quality.