• Proceedings of the KOSOMBE Conference
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• v.1991 no.11
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• pp.30-33
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• 1991

The object of speech processor for cochlear implants is to deliver speech information to the central nerve system. In this study we have presented the method which simulate speech processing and coding strategy for cochlear implants and simulated two different processing methods to the 12 adults with normal ears. The formant sinusoidal coding was better than the formant pulse coding In the consonant perception test and learning effects.(p < 0.05)

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.13-23
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• 2012

The sound /w/ has been traditionally regarded as an independent segment in Korean regardless of the phonological contexts in which it occurs. There have been, however, some questions regarding whether it is an independent phoneme in /CwV/ context (cf. Kang 2006). The present pilot study examined how Korean /w/ is realized in $/S^*wV/$ context by performing some perception tests. Our assumption was that if Korean /w/ is a part of the preceding complex consonant like $/C^w/$, it should be more or less uniformly articulated and perceived as such. If /w/ is an independent segment, it will be realized with speaker variability. Experiments I and II examined the identification rates as "labialized" of the spliced original stimuli of $/S^*-V/$ and $/S^{w*}-^wV/$, and the cross-spliced stimuli $/S^{w*}-V/$ and $/S^*-^wV/$. The results showed that round qualities of /w/ are perceived at significantly different temporal point with speaker and context variability. We therefore conclude that /w/ in $/S^*wV/$ context is an independent segment, not a part of the preceding segment. Full-scale examination of the production test in the future should be performed to verify the conclusion we suggested in this paper.

• Speech Sciences
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• v.14 no.4
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• pp.25-39
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• 2007

The present study investigated some perceptual phonetic attributes of two Korean stop types, aspirated and lax, in medial position of an accentual phrase. The intonational pattern across syllables (Jun, 1993) is argued to depend on the type of stop (aspirated vs. lax) only in the initial position of an accentual phrase. In Kang & Dilley (2007), we showed that significant differences between aspirated and lax stops in medial position of an accentual phrase exist in closure duration, voice-onset time, and fundamental frequency (F0) values for post-stop vowels. In the present perception experiment, we investigated whether these phonetic attributes contribute to the perception of these two types of stops: The closure durations and/or F0's of post-stop vowels on accentual-phrase medial words were altered and twenty native Korean speakers then judged these words as beginning with an aspirated or lax stop. Both closure duration and F0 significantly affected judgments of stop identity. These results indicate that a wider range of acoustic cues that distinguish aspirated and lax Korean stops in production also plays a role in perception. To account for these results we suggest some phonetic and phonological models of consonant-tone interactions for Korean.

• The Journal of the Korea Contents Association
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• v.9 no.1
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• pp.455-464
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• 2009

Based on the observation that Korean speakers of English have difficulties in producing English fricatives, a perception experiment was designed to investigate whether Korean speakers also have difficulties perceiving English labial consonants including fricatives. Forty Korean college students were asked to perform a multiple-choice identification test. The consonant perception test consisted of nonce words which contained English labial consonants [p, b, f, v] in 4 different prosodic locations: initial onset position, intervocalic position before stress, intervocalic position after stress, and final coda position. The general perception pattern was that the mean accuracy rates were higher in strong position like CV and VCVV than in weak position like VC and VVCV. The difficulties in perceiving the English targets resulted mainly from bidirectional manner confusion between stop and fricative across all prosodic locations. The other types of misidentification were due to place confusion as well as voicing confusion. Place confusion was generated mostly by the target [f] in all prosodic position due to acoustic properties. Voicing confusion was heavily influenced by prosodic position. The misperception of the participants was accounted for by phonetic properties and/or the participants' native language properties.

• Phonetics and Speech Sciences
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• v.6 no.1
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• pp.11-19
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• 2014

The focus of this study was to investigate whether there is a position effect on identification accuracy of L2 consonants by Korean listeners and to examine how Korean listeners perceive the phonetic properties of initial and final consonants produced by a Korean learner of English and an English native speaker. Most studies examining L2 learners' perception of L2 sounds have focused on the segmental level but very few studies have examined the role of prosodic position in L2 learners' perception. In the present study, an identification test was conducted for English consonants /p, t, k, f, ɵ, s, ʃ/ in CVC prosodic structures. The results revealed that Korean listeners identified syllable-initial consonants more accurately than syllable-final consonants. The perceptual accuracy in syllable initial consonants may be attributable to the enhanced phonetic properties in the initial consonants. A significant correlation was found between error rates and F2 onset/offset for stops and fricatives, and between perceptual accuracy and RMS burst energy for stops. However, the identification error patterns were found to be different across consonant types and between the different language speakers. In the final position, Korean listeners had difficulty in identifying /p/, /f/, /ɵ/, and /s/ when they were produced by a Korean speaker and showed more errors in /p/, /t/, /f/, /ɵ/, and /s/ when they were spoken by an English native speaker. Comparing to the perception of English consonants spoken by a Korean speaker, greater error rates and diverse error patterns were found in the perception of consonants produced by an English native speaker. The present study provides the evidence that prosodic position plays a crucial role in the perception of L2 segments.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.1092-1096
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• 2009

While Korean allows the same consonants at the coda of the preceding syllable and at the onset of the following syllable, English does not allow the geminate consonant in the same position. Due to this difference between Korean and English, Korean learners of English tend to incorrectly produce geminate consonants for English geminate graphemes as in summer. Based on this observation, a pilot study was designed to investigate how Korean learners of English perceive and produce English doubleton graphemes and singleton graphemes. Twenty Korean college students were asked to perform a forced-choice perception test as well as a production test for the 36 real word stimuli which consist of near minimal pairs of singleton and doubleton graphemes. The result showed that the accuracy rates for the word with singleton graphemes were relatively high both in perception and production (78.6% and 76.1%, respectively), while those for the word with doubleton graphemes were low both in perception and production (55.3% and 61.7%, respectively). Also, spectrographic analyses were provided where more production errors were witnessed in doubleton grapheme words than singleton grapheme words.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.8
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• pp.782-791
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• 1991

In the fields of pattern recognition such as speech recognition, several new techniques using Artifical Neural network Models have been proposed and implemented. In particular, the Multilayer Perception Model has been shown to be effective in static speech pattern recognition. But speech has dynamic or temporal characteristics and the most important point in implementing speech recognition systems using Artificial Neural Network Models for continuous speech is the learning of dynamic characteristics and the distributed cues and contextual effects that result from temporal characteristics. But Recurrent Multilayer Perceptron Model is known to be able to learn sequence of pattern. In this paper, the results of applying the Recurrent Model which has possibilities of learning tedmporal characteristics of speech to phoneme recognition is presented. The test data consist of 144 Vowel+ Consonant + Vowel speech chains made up of 4 Korean monothongs and 9 Korean plosive consonants. The input parameters of Artificial Neural Network model used are the FFT coefficients, residual error and zero crossing rates. The Baseline model showed a recognition rate of 91% for volwels and 71% for plosive consonants of one male speaker. We obtained better recognition rates from various other experiments compared to the existing multilayer perceptron model, thus showed the recurrent model to be better suited to speech recognition. And the possibility of using Recurrent Models for speech recognition was experimented by changing the configuration of this baseline model.

• The Journal of the Acoustical Society of Korea
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• v.40 no.1
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• pp.18-30
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• 2021

The ultimate goal of the present study is to establish the acoustical performance standards of classroom for the elderly who are incomplete hearing people. As a pilot survey, the present study was conducted to investigate the listening environment and the actual condition of speech perception performance of education facilities for elderly, Acoustic performances of two education facilities for elderly in Cheongju were measured and questionnaire survey was done to elderly people. Also, speech intelligibility tests were undertaken by Consonant Vowel Consonant (CVC) and Phonetically Balanced Words (PBW) methods. The questionnaire survey showed that the elderly were satisfied with the listening environment of the educational facilities in general. Also, it was found that acoustical performances satisfy with the acoustic criteria of general classrooms in Korea. However, the results of the speech intelligibility test showed that the scores of elderly were significantly lower than twenties with normal hearing. It was also revealed that the scores are reduced as the age increases. Thus, it was concluded that the acoustical performance standards of educational facilities for the normal hearing were not suitable for educational facilities for the elderly.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.460-466
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• 2010

It is well-known that Korean EFL learners have difficulties in producing English fricatives which are not in the inventory of Korean and consequently tend to replace English fricatives with stops. The purpose of this paper is to investigate whether Korean students also have difficulties perceiving English anterior coronal consonants including fricatives. To this end, forty Korean college students participated in an identification test which consisted of 24 nonce words with English anterior coronal consonants in 4 different prosodic locations (CV, VC, VCVV,VVCV). It was shown that the mean accuracy rates were higher in strong position like CV and VCVV than in weak position like VC and VVCV, providing confusion matrices for each target consonant. It was also found that Korean participants had a great difficulty identifying English[$\theta$] and [$\eth$], which are novel in Korean. Importantly, the confusion patterns found in the perception test tended not to be identical with those found in the previous production studies in that both stops and fricatives were misperceived as fricatives while fricatives were misproduced as stops. Further, perceptual devoicing and intervocalic voicing were attested inVC and intervocalic position, respectively. Based on the findings of this study, pedagogical implications were drawn.

• Journal of Korean language education
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• v.28 no.2
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• pp.37-60
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• 2017

This research has its basis with focus on the way Korean native speakers recognize Chinese Korean-learners' pronunciation. The objective of the study is to lay the cornerstone for establishing effective teaching-learning strategies for the education of the Korean phonetic system. In this study, the results of the experiment are presented which shows how native speakers of Korean identify Chinese Korean-learners' pronunciation of consonants. In the first place, stimulation tones were created from the original utterances of Chinese Korean-learners and seven scripts were made through the Pratt program. In addition, the subjects were asked to choose what the phonetic materials sounded like. The results of the research are represented as the ratio of frequency of Korean native speakers' response to each utterance to the total frequency. In addition, the paired t-test was taken in order to explore any relatedness to the changes in the level of proficiency of the Korean phonetic system, ranging from beginners to advanced learners. The outcome shows that the mistakes which Chinese Korean-learners make in pronouncing the consonants of Korean are relatively well-reflected in Korean native speakers' auditory cognitive reactions. To put it concretely, there is some difficulty in differentiating lax consonants from aspirates in the cases of plosives and affricates, but relatively little trouble with fortes. However, it is revealed that there is also a slight difference in relation to articulatory positions in detailed aspects. To provide an effective teaching method for the Korean phonetic system, it is essential to comprehend learners' phonetic mistakes through the precise analysis of data in terms of 'production.' Also, a more meticulous observation of 'phenomena' must be made through verification from the view of 'reception,' as attempted in this study. A more thorough diagnosis by applying methodology makes it possible to lay the foundation for developing effective teaching-learning strategies for the instruction of the Korean phonetic system. This study has its significance in making such attempts.