• Speech Sciences
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• v.9 no.4
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• pp.175-185
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• 2002

The purpose of this study was to investigate the acoustic durations of Korean vowels followed by either voiced or voiceless consonants. Six healthy adult speakers (2 females and 4 males) recorded nonsense syllables in which voiced (/b, d, g/) or voiceless (/p', t', k', $p^{h},t^{h},k^{h}$) consonants follow three different vowels (/i, a, u/) embedded in a carrier phrase. Results showed that vowels preceding voiced consonants (e.g., haba) were significantly longer in duration than those preceding voiceless consonants (e.g., hiP' a or $hip^{h}a$). Also vowels were longer in duration when occurring before velar-stops than before bilabial-stop and dental-stops. Finally, the duration of the low vowel (/a/) was substantially longer than that of the high vowels (/i, u/). These findings may be applicable to speech synthesis or therapy.

• Phonetics and Speech Sciences
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• v.9 no.4
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• pp.35-41
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• 2017

The existence and the extent of vowel length difference before voiced/voiceless consonants in English and Korean are examined in three groups: (1) Korean-speaking Americans (group A), (2) immigrants who moved to the U.S. in their early teens (group I), and (3) Koreans who have been in the U.S. for less than 3 years (group K). 14 subjects were recorded reading 10 English and 10 Korean sentences. The results show that the three groups exhibit different patterns of the vowel length difference: Group A shows a very strong tendency of vowel lengthening before voiced consonants in both English and Korean, while Group I shows less degree of vowel lengthening, and Group K shows almost no tendency of vowel length difference in both languages. This strongly suggests that, (1) unlike English, Korean does not have the vowel length difference depending on the following consonants, and (2) the vowel lengthening effect observed in Korean (L2) speech in group A may be the result of transfer of the phonetic trait acquired in English (L1). It also implies that, in teaching pronunciation, some facts such as the vowel length difference cannot be expected to be acquired automatically for the learners of English, but have to be taught explicitly.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.409-414
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• 1996

The aim of this paper is to research on the actual condition of Koreans' Spanish consonants pronunciation with an emphasis on describing the phonetic different of Korean speakers and Spanish speakers. 40 Spanish words were chosen for the speech sampling, and 10 Spanish majoring Korean students from Seoul or Kyunggi Province and 3 Spanish speakers form Castile, Spain participated in the interview. The most noticeable phonetic differences of Korean speakers' pronunciation comparing with Spanish speakers are abstracted as follows: 1) The voiced stops are pronounced voiceless or weak voiced. 2) The voiced stops are slightly aspirated. 3) The length of voiceless consonants is quite longer than the length of proceeding vowel. 4) Fricatives and affricates are somewhat fronter, and weaker in the degree of friction. 5) There is a strong tendency to geminate dental lateral /l/ such as 'pelo' and to vocalize palatal lateral /$\rightthreetimes$/ such as 'calle' 6) Unlike in Spanish speech flap $\mid$r$\mid$ and trill [r] are pronounced similarly in Korean speech.

• Cross-Cultural Studies
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• v.39
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• pp.381-406
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• 2015

Russian nasal consonants / m /, / n / have a feature value not only [+consonant] in common with obstruents, but also [+sonorant] in common with vowels. Nasal / m /(bi-labial) and / n /(dental) have the same place of articulation but different manner of articulation. The feature value of / m / is [+cons, +son, +nas, +ant, -cor, -high, -low, -back, -cont, -del, rel, -strid, +voic], and that of / n / is [+cons, +son, +nas, +ant, +cor, -high, -low, -back, -cont, -del, rel, -strid, + voic]. There is a difference in feature [cor] value of / m / and / n /. In this study it is confirmed that it is a fact that the Russian nasal consonants behave differently from the other consonants in each phonological phenomenon due to their phonological characteristics. The preceding voiced obstruent is changed to an unvoiced one in a process where the last voiceless obstruent in the consonant cluster ' voiced obstruent + nasal /m/ + voiceless obstruent' skips the nasal consonant and spreads its feature value to the preceding voiced obstruent transparently because of the feature [+sonorant] of the nasal consonant. The coronal nasal /n/ participates in a palatalization with the following palatal actively and palatalize preceding plain consonants passively because of markedness hierarchy such as 'Velar > Labial > Coronal'. But the labial nasal /m/ is palatalized with the following velar palatal actively and participates in a palatalization with the following coronal palatal passively. This result helps us confirm the phonological difference of /m/ and /n/ in a palatalization. When the a final consonant is nasal, the unvoicing phenomenon of a final consonant doesn't occur. In such a case as cluster 'obstruent + nasal' the feature value [voiced] of the preceding obstruent doesn't change, but the following nasal can assimilate into the preceding obstruent. When continuing the same nasals / -nn- / in a consonant cluster, the feature value [+cont] of a weak position leads the preceding nasal / n / to be changed into [-cont] / l /. Through the analysis of the frequency of occurrences of consonants in syllabic onsets and codas that should observe the 'Sonority Sequence Principle', the sonority hierarchy of nasal consonants has been confirmed. In a diachronic perspective following nasal / m /, / n / there is a loss of the preceding labial stop and dental stop. But in clusters with the velar stop+nasal, the two-component cluster has been kept phonetically intact.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.91-95
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• 2005

The aim of this paper is to investigate the effects of postvocalic voicing(Contrasting voiceless fricative and affricate with voiced fricative and affricate) on vowel duration. In particular we focused on the durational differences between vowels followed by voiceless and voiced consonants across three groups of speakers: English speakers, English bilinguals and Korean learners of English. the result of experimental I showed that durations of vowels preceding voiced fricative and affricates as well as voiced stops are significantly longer than those preceding voiceless counterparts. Experiment Ⅱ indicated that as the subjects exposed themselves longer to English speaking society, their pronunciation was increasingly similar to those of English native speakers.

• Korean Linguistics
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• v.79
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• pp.63-89
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• 2018

This study explores contrastive relation among voiced bilabial fricative [${\ss}$], voiceless bilabial stop [p] and glide [w] in Middle Korean consonant system based on Probabilistic Model. Preceding researches about voiced bilabial fricative [${\ss}$] proposed two influential arguments. One is voiced bilabial fricative [${\ss}$] was an independent phoneme, the other is it was not an independent phoneme but an allophone of voiceless bilabial stop [p] in Middle Korean. This study applies Probabilistic Phonological Relationship Model (PPRM) for solving the problem of dichotomy about contrastive and allophonic relations. The analysis result of the contrastive entropy by PPRM suggests that voiced bilabial fricative [${\ss}$] was just an allophone of voiceless bilabial stop [p] or glide [w] in Middle Korean. Comparing the entropies between [p] and other consonants with the entropies between [${\ss}$] and other consonants, a continuum defined in terms of entropy reveals that [${\ss}$] in Middle Korean was more allophonic than phonemic.

• Phonetics and Speech Sciences
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• v.14 no.1
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• pp.1-11
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• 2022

The purpose of this study is to investigate the difference of vowel duration due to the voicing of word-final consonants in English and its relation to the types of word-final consonants (stops vs. fricatives), (partial) devoicing, and stop releasing. Addtionally, this study attempts to interpret the findings from the functional view that the vowels before voiced consonants are produced with a longer duration in order to enhance the salience of the voicing of word-final consonants. This study conducted a recording experiment with English native speakers, and measured the vowel duration, the degree of (partial) devoicing of word-final voiced consonants and the release of word-final stops. First, the results showed that the ratio of the duration difference was not influenced by the types of word-final consonants. Second, it was revealed that the higher the degree of (partial) devoicing of word-final voiced consonants, the longer vowel duration before word-final voiced consonants, which was compatible with the prediction based on the functional view. Lastly, the ratio of the duration difference was greater when the word-final stops were uttered with the release compared to when uttered without the release, which was not consistent with the functional view. These results suggest that it is not sufficient enough to explain the voicing effect by its function of distinguishing the voicing of word-final consonants.

• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1299-1304
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• 2000

In a speed coding system using excitation source of voiced and unvoiced, it would be involved a distortion of speech quality in case coexist with a voiced and an unvoiced consonants in a frame. So, I propose TSIUVC(Transition Segment Including UnVoiced Consonant) searching, extraction ad approximation-synthesis method in order to uncoexistent with a voiced and unvoiced consonants in a frame. This method based on a zerocrossing rate and pitch detector using FIR-STREAK Digital Filter. As a result, the extraction rates of TSIUVC are 84.8% (plosive), 94.9%(fricative), 92.3%(affricative) in female voice, and 88%(plosive), 94.9%(fricative), 92.3%(affricative) in male voice respectively, Also, I obain a high quality approximation-synthesis waveforms within TSIUVC by using frequency information of 0.547kHz below and 2.813kHz above. This method has the capability of being applied to speech coding of low bit rate, speech analysis and speech synthesis.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.4
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• pp.33-41
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• 1997

Korean unvoiced phonemes consist of nonstationary parts comparing that the vowels and nasal consonants consist of quasi-stationary part. And some phonemes, which have smae point of articulation but differnt manner of articulation, has similar characteristics, so it makes to be hard to distinguish each other. A new method usin gchanges and characteristics of acoustic properties of these phonemes to improve recognition rate are proposed. And because these changes and cahracteristics evidently occur in continuous speech except some unvoiced consonants are articulated as voiced phoneme in case to be used as an midial between voiced phonemes, this method can be applied easily. The features of the frames extracted to represent each phonemes are used asinputs to the hierarchical neural network. And with these results final decision for phoneme recognition is made thorugh post processing which the new method is applied to. Through the experimental recognition results for 9 unvoiced consonants which belong to bilabial, alveolar, and velar phoneme series, 89.4% recognition rate to distinguish in same phoneme series is obtained, and 85.6% recognition rate is obtained in case of including cistinguishing phoneme series.

• Proceedings of the Acoustical Society of Korea Conference
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• 1991.06a
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• pp.73-77
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• 1991

As the basic analysis to solve the stop consonants in phoneme based speech recognition using Back Propagation learning algorithm, changes in hidden units, training set and iteration. Also we propose an efficient processing method of separation between consonants and vowels.