Byunggon Yang

An acoustical study of Korean monophthongs produced by male and female speakers

The first three formants of the ten Korean monophthongs were studied. The vowels were produced by 20 male and female speakers in an ‖hVda‖ (V=vowel) context. Then the male–female variations in the Korean formant data were examined. The uniform scaling method resulted in less than a 6% difference between the scaled and reference data. A regression analysis showed that the slope of a regression equation with a small intercept near the origin could be used for the uniform scale factor.

An acoustical study of English word stress produced by Americans and Koreans

Acoustical correlates of stress can be divided into duration, intensity, and fundamental frequency. This study examined the acoustical difference in the first two syllables of stressed English words produced by ten American and Korean speakers. The Korean subjects scored very high in TOEFL. They read, at a normal speed, a fable from which the acoustical parameters of eight words were analyzed. In order to make the data comparison meaningful, each parameter was collected at 100 dynamic time points proportional to the total duration of the two syllables. Then, the ratio of the parameter sum of the first rime to that of the second rime was calculated to determine the relative prominence of the syllables. Results showed that the durations of the first two syllables were almost comparable between the Americans and Koreans. However, statistically significant differences showed up in the diphthong pronunciations and in the words with the second syllable stressed. Also, remarkably high r‐squared values were found...

Production and perception of English vowels

This study examined the relation between production of nine English vowels and perception of the synthesized vowels by 14 American male and female speakers. Fant’s bandwidth equations were employed to dynamically tune to the varied formant frequency values. A remarkable r2 value was obtained from the regressional analysis between the center formant frequency values at which the subjects perceived the same vowel quality from the discriminatory test and the formant values of the synthesis models. Males and females perceived the synthesized vowels in the same way with converging center formant values and similar ranges of the same vowel quality. There was a strong link between production and perception of male and female speakers. The average r2 value was very high, which suggests a very lawful relation between production and perception. From the individual analyses we found that listeners adjusted the criteria for vowel discrimination in relation to their own vocal tracts. This result suggests that speaker ...

Vowel perception by formant variation

The acoustic parameters of six Korean vowels produced by a healthy male subject with normal hearing were analyzed to synthesize the six vowels by a formant synthesis method. The f0, amplitude envelopes, and the first six formant values were elaborately matched to the those of the original vowels. Then, F1 and F2 values of the synthesis file were modified by 50 Hz over and under the original values but not interfering with adjacent formants. F3 varied 500 Hz over and under the original values by 100 Hz to obtain 270 stimuli. Twenty male and female subjects in a quiet room listened to the original vowel followed by the corresponding synthesized one 0.5 s later and judged whether they sounded qualitatively ‘‘similar’’ or ‘‘different.’’ From the experiment, it was found that male subjects responded ‘‘similar’’ within the range of variance by an average of 163 Hz for F1, 415 Hz for F2; and 843 Hz for F3. Female subjects showed 40‐Hz higher range than males. The ranges supported the nonlinearity of the human au...

Phoneme distribution and phonological processes of orthographic and pronounced phrasal words by syllable structure in the Seoul Corpus

This study examined the phoneme distribution and phonological processes of orthographic and pronounced phrasal words according to syllable structure in the Seoul Corpus of spontaneous speech produced by 40 Korean speakers. To achieve the goal, the phrasal words were extracted from the transcribed label scripts of the Seoul Corpus using Praat. Then, the onsets, peaks, codas, and syllable types of the phrasal words were analyzed using an R script. Results revealed that k0 was most frequently used as an onset in both orthographic and pronounced phrasal words. Also, aa was the most favored vowel in the Korean syllable peak with fewer phonological processes in its pronounced form. For the codas, nn accounted for 34.4% of the total pronounced phrasal words and was the varied form. From syllable type classification of the Corpus, CV appeared to be the most frequent type followed by CVC, V, and VC from the orthographic forms. Overall, the onsets were prevalent in the pronunciation more than the codas. From the re...

Phoneme distribution and syllable structure of entry words in the Carnegie Mellon University Pronouncing Dictionary

This study explores the phoneme distribution and syllable structure of entry words in the CMU Pronouncing Dictionary to provide linguists with fundamental phonetic data on English word components. Entry words in the dictionary file were syllabified using an R script and examined to obtain the following results: First, English words preferred consonants to vowels in their word components. In addition, monophthongs occurred much more frequently than diphthongs. When all consonants were categorized by manner and place, the distribution indicated the frequency order of stops, fricatives, and nasals according to manner and that of alveolars, bilabials and velars according to place. Second, from the analysis of syllable structure, two-syllable words were most favored, followed by three- and one-syllable words. Of the words in the dictionary, 92.7% consisted of one, two, or three syllables. Third, the English words tended to exhibit discord between onset and coda consonants and between adjacent vowels. Dissimila...

Spectral characteristics and formant bandwidths of English vowels produced by American males with different speaking styles

Speaking styles tend to have an influence on spectral characteristics of produced speech. There are not many studies on the spectral characteristics of speech because of complicated processing of too many spectral data. This study examined spectral characteristics and formant bandwidths of English vowels produced by nine American males with different speaking styles: clear or conversational styles; high- or low-pitched voices. PRAAT was used to collect pitch-corrected long-term averaged spectra and bandwidths of the first two formants of 11 vowels in the speaking styles. Results showed that the spectral characteristics of the vowels varied systematically according to the speaking styles. The clear speech showed higher spectral energy of the vowels than that of the conversational speech while the high-pitched voice did the same over the low-pitched voice. Second, there was no statistically significant difference between B1 and B2 in the speaking styles. B1 was generally lower than B2 reflecting the source spectrum and radiation effect. However, there was a statistically significant difference in B2 between the front and back vowel groups. The author concluded that spectral characteristics reflect speaking styles systematically while bandwidths measured at a few formant frequency points do not reveal style differences properly.

Relative distances among English front vowels produced by Korean and American speakers

This study examined the relative distances among English front vowels in a message produced by 47 Korean and American speakers from an internet speech archive in order to provide better pronunciation skills for Korean English learners. The Euclidean distances in the vowel space of F1 and F2 were measured among the front vowel pairs. The first vowel pair [i-ɛ] was set as the reference from which the relative distances of the other two vowel pairs were measured in percent in order to compare the vowel sounds among speakers of different vocal tract lengths. Results show that F1 values of the front vowels produced by the Korean and American speakers increased from the high front vowel to the low front vowel with differences among the groups. The Korean speakers generally produced the front vowels with smaller jaw openings than the American speakers did. Second, the relative distance of the high front vowel pair [i-ɪ] showed a significant difference between the Korean and American speakers while that of the lo...

An acoustical study of American English diphthongs.

English diphthongs are usually produced with more than one vocal tract shape. This study attempts to collect acoustical data of English diphthongs published by Hillenbrand et al. (1995) online and to examine acoustic features of the diphthongs for phoneticians and English teachers. 63 American males and females were chosen after excluding those subjects with different target vowels or ambiguous formant tracks. The author used PRAAT to obtain the acoustical data systematically at 11 equidistant timepoints over the diphthongal segment. Results show that the formant trajectories of the diphthongs produced by the American males and females appeared quite similar. When the female formant values were uniformly normalized to those of the males, almost a perfect collapse occurred. Second, the diphthongal movements on the vowel space appeared not linear due to the coarticulatory gesture for the following consonant. Third, the average duration of the diphthongs produced by the females was 1.156 times longer than th...

An acoustical comparison of English tense and lax vowels.

Several studies on the pronunciation of English vowels point out that Korean learners have difficulty producing English tense and lax vowel pairs. The acoustic comparisons of those studies are mostly based on the formant measurement at one time point of a given vowel section. However, the English lax vowels usually show dynamic changes across their syllable peaks and subjects’ English levels account for various conflicting results. The purposes of this paper are to compare the temporal duration and dynamic formant tracks of English tense and lax vowel pairs produced by five Korean and five American males. Results showed that both the Korean and American males produced the vowels with comparable durations. The duration of the front tense‐lax vowel pair was longer than that of the back vowel pair. From the formant track comparisons, the American males produced the tense and lax pairs much more distinctly than the Korean males. The results suggest that the Korean males should pay attention to the F1 and F2 m...