• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.91-99
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• 2014

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 much spectral data. The purpose of this study was to examine 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 eleven 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. In addition, front and back vowel groups showed different spectral characteristics. Secondly, there was no statistically significant difference between B1 and B2 in the speaking styles. B1 was generally lower than B2 when 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. Further studies would be desirable to examine how people would evaluate different sets of synthetic vowels with spectral characteristics or with bandwidths modified.

• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.189-194
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• 2014

Objective: This study aims to investigate the speech rate, the length of a pause, habitual pitch, and voice intensity of motherese. Subjects and Methods: The research participants comprised 20 mothers (mean age 33 years). Speech data were collected and analyzed using the Real-time Pitch software (KayPENTAX(R)). Results: The average speech rate was 5.33 syllables per second without their infant present and 4.26 syllables per second with their infant present. The average pause length was 1.09 s without their infant present and 1.56 s with their infant present. The average habitual pitch was 199.79 Hz without their infant present and 227.15 Hz with their infant present. The average voice loudness was 61.09 dB without their infant present and 64.49 dB with their infant present. Conclusion: This study presented clinical information for efficiently managing the speech therapy issues of infants and children. This includes proper acoustic and phonological information to recommend to main caregivers.

• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.67-77
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• 2014

This study investigated (1) whether Korean learners of English use discourse-level prosody in L2 production as native speakers of English do, and (2) whether discourse-level prosody is also found in the Korean language, as is evident in the prosody of native speakers of English. The study compared the production of the same 15 sentences in two types of reading materials, sentence-level and discourse-level. This study analyzed the onset pitch, sentence mean pitch and pause length to examine the paratone (intonational paragraph) realization in discourse-level speech. The results showed that in L2 discourse-level prosody, the Korean speakers were limited in displaying paratone and did not made significant difference between sentence-level and discourse-level prosody. On the other hand, in L1 discourse-level text, both English and Korean participants demonstrated paratone using pitch. However, there were differences in using prosodic cues between two groups. In using pauses, the ES group paused longer before both the orthographically marked and not marked topic sentences. The KS group paused longer only before the orthographically marked topic sentence in both L1 and L2 text reading. In the comparison of sentence-level and discourse-level prosody, the topic sentences were marked by different prosodic cues. English participants used higher sentence mean pitch, and the Korean participants used higher onset pitch.

• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.79-90
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• 2014

An intonation curve stylization was used for an acoustical analysis of English speech. For the analysis, acoustical feature values were extracted from 1,848 utterances produced with normal and fast speech rate by 28 (12 women and 16 men) native speakers of English. Men are found to speak faster than women at normal speech rate but no difference is found between genders at fast speech rate. Analysis of pitch point features has it that fast speech has greater Pt (pitch point movement time), Pr (pitch point pitch range), and Pd (pitch point distance) but smaller Ps (pitch point slope) than normal speech. Men show greater Pt, Pr, and Pd than women. Analysis of sentence level features reveals that fast speech has smaller Sr (sentence level pitch range), Sd (sentence duration), and Max (maximum pitch) but greater Ss (sentence slope) than normal speech. Women show greater Sr, Ss, Sp (pitch difference between the first pitch point and the last), Sd, MaxNr (normalized Max), and MinNr (normalized Min) than men. As speech rate increases, women speak with greater Ss and Sr than men.

• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.17-26
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• 2014

The present study examined epenthetic vowels produced by Korean learners of English in read sentences, in terms of acoustic measures and extra-phonological factors. The results demonstrated three main findings. First, epenthetic vowels had relatively high F1 values and a wide range of F2 values. Most of the epenthetic vowels were inserted near Korean high central vowels, but some vowels were inserted near front vowels due to co-articulation with surrounding vowels. Second, vowel epenthesis was affected by the context. The results showed that the epenthesis was frequently seen with word junctions between obstruents (e.g., stops-fricatives). Third, Korean learners were not affected by English background and were very weakly affected by orthography. English experience, which is one of the extra-phonological factors, was not related to epenthesis production. However, orthography, the other extra-phonological factor, very weakly affected the amount of epenthesis production. Nine percent of all epenthesis production was affected by the English past-tense suffix '-ed'; approximately 70% of the participants were affected by this suffix. The findings of the present study contributed to understanding vowel epenthesis. First, the study revealed that the epenthetic vowels produced by Korean learners of English were close to the high central vowel, supporting previous studies that the epenthetic vowel is quite close to the shortest vowel. Second, the study examined the various phonetic environments of epenthetic vowels, revealing that vowel epenthesis occurred more frequently in a certain phonetic circumstance.

• Phonetics and Speech Sciences
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• v.6 no.4
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• pp.171-179
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• 2014

Purposes: Speech acceptability means the subjective judgement of listeners regarding the naturalness and normality of the speech. The purpose of this study was to determine the predicting variables for speech acceptabilities of children with cochlear implants. Methods: Twenty seven children with CI participated. They had profound pre-lingual hearing loss without any additional disabilities. The mean of chronological ages was 8;9, and mean of age of implantation was 2;11. Speech samples of reading and spontaneous speech were recorded separately. Twenty college students who were not familiar to the speech of deaf children evaluated the speech acceptabilities using visual analog scale. 1 segmental (articulation) and 6 suprasegmental features (pitch, loudness, quality, resonance, intonation, and speaking rate) of speech were perceptually evaluated by 3 SLPs. Correlation and multiple regression analysis were performed to evaluate the predicting variables. Results: The means of speech acceptability for reading and spontaneous speech were 73.47 and 71.96, respectively. Speech acceptability of reading was predicated by the severity of intonation and articulation. Speech acceptability of spontaneous speech was predicated by the severity of intonation and loudness. Discussion and conclusion: Severity of intonation was the most effective variable to predict the speech acceptabilities of both reading and spontaneous speech. A further study would be necessary to generalize the result and to apply this result to intervention in clinical settings.

• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.109-119
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• 2014

This article represents a first step in a large study aimed at elucidating the relationship between production and perception involved in sound change of /o/ in (Seoul) Korean. In this paper we present the results of a production study and a perception experiment. For the production study we examined vowel production data of 20 young adult speakers, measuring the first and second formants, then conducted a discriminant analysis based on those values. In terms of their F1-F2 values, the distribution of /o/ and /u/ were close, and even overlapping in some circumstances, which is consistent with the literature. This tendency was more apparent among the female speakers than the males. Moreover, with the females' distributions, /o/ was frequently categorized as /u/, suggesting that the direction of the sound change is indeed increasing from /o/ to /u/. Next, to investigate the effects of this proximity on perception, we used the production data of five randomly selected speakers from the production study as stimuli for a perception experiment in which 21 young adult native speakers of (Seoul) Korean performed a vowel identification task and provided a Goodness rating on a 5-point scale. We found that while rates of correctness were high, when these correctness scores were weighted by the Goodness rating, these "weighted correctness" scores were lower in some cases, indicating a degree of confusion in distinguishing between the two vowels.

• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.91-99
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• 2014

Although it is well documented that patients with cochlear implant experience hearing difficulties when processing their first language, very little is known whether or not and to what extent cochlear implant patients recognize segments in a second language. This preliminary study examines how Korean learners of English identify English segments in a normal hearing and cochlear implant simulation conditions. Participants heard English vowels and consonants in the following three conditions: normal hearing condition, 12-channel noise vocoding with 0mm spectral shift, and 12-channel noise vocoding with 3mm spectral shift. Results confirmed that nonnative listeners could also retrieve spectral information from vocoded speech signal, as they recognized vowel features fairly accurately despite the vocoding. In contrast, the intelligibility of manner and place features of consonants was significantly decreased by vocoding. In addition, we found that spectral shift affected listeners' vowel recognition, probably because information regarding F1 is diminished by spectral shifting. Results suggest that patients with cochlear implant and normal hearing second language learners would experience different patterns of listening errors when processing their second language(s).

• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.81-89
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• 2014

Korean English learners tend to have difficulty perceiving and producing English vowels. The purpose of this study is to examine a link between perceived and produced vowel spaces of Korean learners of English. Sixteen Korean male and female participants perceived two sets of English synthetic vowels on a computer monitor and rated their naturalness. The same participants produced English vowels in a carrier sentence with high and low pitch variation in a clear speaking mode. The author compared the perceived and produced vowel spaces in terms of the pitch and gender variables. Results showed that the perceived vowel spaces were not significantly different in either variables. Korean learners perceived the vowels similarly. They did not differentiate the tense-lax vowel pairs nor the low vowels. Secondly, the produced vowel spaces of the male and female groups showed a 25% difference which may have come from their physiological differences in the vocal tract length. Thirdly, the comparison of the perceived and produced vowel spaces revealed that although the vowel space patterns of the Korean male and female learners appeared similar, which may lead to a relative link between perception and production, statistical differences existed in some vowels because of the acoustical properties of the synthetic vowels, which may lead to an independent link. The author concluded that any comparison between the perceived and produced vowel space of nonnative speakers should be made cautiously. Further studies would be desirable to examine how Koreans would perceive different sets of synthetic vowels.

• Phonetics and Speech Sciences
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• v.6 no.3
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• pp.73-77
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• 2014

The purpose of this study is to investigate the differences of the speech rate according to the area in the perceptual and acoustic analysis. This study examines regional variation in overall speech rate and articulation rate across speaking situations (picture description, free conversation and story retelling) with 14 normal adult (7 in Gyeongnam and 7 in Honam area). The result of an experimental investigation shows that the perceptual speech rate differs significantly between two regional varieties of Koreans with a picture description examined here. A group of Honam speakers spoke significantly faster than a group of Gyeongnam speakers. However, the result of the acoustic analysis shows that the speech rate of the two groups did not differ. And there were significant regional differences in the overall speech rate and articulation rate on the other two speaking situation, free conversation and story retelling. It suggest that we have to study perceptual evaluation with regard to the free conversation and story retelling in future research, and based on the results of this study, a variety of researches on the speech rate will be needed on the various conditions, including various area and SLPs who have wider background and experiences. It is necessary for SLPs to train and experience more to assess patients properly and reliably.