• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.37-52
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• 2011

This study investigates patterns of the alignment of the accentual peaks in bisyllabic words of the CVNCV, CVNV, and CVNNV structures in North Kyungsang Korean. Based on the tonal alignment, patterns of the F0 pitch excursion are discussed relative to one another. Issues are addressed concerning how the tonal targets are aligned, and how the tonal specifications of nasals in postvocalic, intervocalic, and prevocalic environments are supplied in the LH, HL, and HH classes. Tonal specification of nasals in various environments is accounted for by extension of the L target, displacement of the pitch peak, and interpolation between two tonal targets, depending on the tonal class. The results in this study provide preliminary evidence that the categorical alignment of the tonal targets is implemented by simply checking the presence or absence of a nasal before or after the nucleus vowel on the segmental string, without reference to the constituency of the nasal in the syllable structure. However, the prosodic structure has a key role to play in explaining speaker-dependent variations in the tonal alignment. Sensitivity to tautosyllabicity has an effect on the shape of the F0 contour, and disparity in the patterns of the pitch excursion is represented as a function of syllable structure correlated with segmental composition of the nasal.

• The Journal of the Acoustical Society of Korea
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• v.12 no.4
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• pp.14-20
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• 1993

본 논문에서는 주변 소음을 감소시키고 표적원의 방사음으로부터 tonal 성분을 추출하기 위한 방법으로서 잡음 정규화 기법에 대하여 연구하였다. 지금까지 알려진 기법들을 정리하였으며, ATW, 최빈치 필터등의 새로운 기법을 도입, 적용하여 그 성능을 평가하였다. 그리고 tonal 성분을 검출하기 위한 임계값 결정을 위해 오경보확률과 검출확률을 시뮬레이션을 통해 구하였다.

• Speech Sciences
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• v.14 no.1
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• pp.37-62
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• 2007

The current study examines the role of post-lexical tonal patterns of a prosodic phrase in word segmentation. In a word spotting experiment, native Korean listeners were asked to spot a disyllabic or trisyllabic word from twelve syllable speech stream that was composed of three Accentual Phrases (AP). Words occurred with various post-lexical intonation patterns. The results showed that listeners spotted more words in phrase-initial than in phrase-medial position, suggesting that the AP-final H tone from the preceding AP helped listeners to segment the phrase-initial word in the target AP. Results also showed that listeners' error rates were significantly lower when words occurred with initial rising tonal pattern, which is the most frequent intonational pattern imposed upon multisyllabic words in Korean, than with non-rising patterns. This result was observed both in AP-initial and in AP-medial positions, regardless of the frequency and legality of overall AP tonal patterns. Tonal cues other than initial rising tone did not positively influence the error rate. These results not only indicate that rising tone in AP-initial and AP_final position is a reliable cue for word boundary detection for Korean listeners, but further suggest that phrasal intonation contours serve as a possible word boundary cue in languages without lexical prominence.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.5
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• pp.915-920
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• 2007

Using the existing algorithms that estimate the background noise, the detection probability for the week tonals is low and for the even week tonals, there is a limit not detected. Therefore it is required to algorithms which can improve the performance of the tonal extraction. Recently, many researches using artificial neural networks in sonar signal processing are performed. We propose a neural network with double feedback that can remove automatically the background noise and detect the even week tonals buried in background noise, therefore not detected by growing the week tonals lastingly for a certain time. For the real underwater target, experiments for the tonal extraction are performed by using the existing algorithms that estimate the background noise and the proposed neural network. As a result of the experiment, a method using the proposed neural network showed the better performance of the tonal extraction in comparison with the existing algorithms.

• The Journal of the Acoustical Society of Korea
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• v.37 no.1
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• pp.39-45
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• 2018

Compressive sensing allows recovering an original signal which has a small dimension of the signal compared to the dimension of the entire signal in a short period of time through a small number of observations. In this paper, we proposed a method for detecting tonal signal which caused by the machinery component of a vessel such as an engine, gearbox, and support elements. The tonal signal can be modeled as the sparse signal in the frequency domain when it compares to whole spectrum range. Thus, the target tonal signal can be estimated by S-OMP (Simultaneous-Orthogonal Matching Pursuit) which is one of the sparse signal recovery algorithms. In simulation section, we showed that S-OMP algorithm estimated more precise frequencies than the conventional FFT (Fast Fourier Transform) thresholding algorithm in low SNR (Signal to Noise Ratio) region.

• Speech Sciences
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• v.15 no.1
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• pp.7-23
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• 2008

This paper investigates tonal patterns of the prosodic constituents of an AP and a PWD in Korean and their relation with the morphological/syntactic structure. Specifically, this paper asks the following questions: First, if there are more than one PWD in an AP, how is each PWD specified in terms of tones? Secondly, in case that there is only one PWD in an AP that consists of several morphemes, is there any preference of the association between tones and the morphemes that constitute that PWD? Thirdly, if an AP dominates a PWD and if a PWD contains at least one morpheme of the lexical category, it follows that an AP should contain at least one morpheme of the lexical category. Can this be verified with the experimental data? In order to answer these questions, Experiment I and II were conducted with the target material consisting of a stem and suffixes that varied in length. The results of this preliminary test show that as the number of syllables in the target material increases, the more number of an AP tonal pattern occurs in it and as a result, in some cases, an AP consisting of suffixes only may occur.

• The Journal of the Acoustical Society of Korea
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• v.35 no.2
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• pp.110-117
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• 2016

Passive sonar systems detect and classify the target by analyzing the radiated noises from vessels. If multiple noise sources exist within the sonar detection range, it gets difficult to classify each noise source because mixture of noise sources are observed. To overcome this problem, a beamforming technique is used to separate noise sources spatially though it has various limitations. In this paper, we propose a new method that uses a FDICA (Frequency Domain Independent Component Analysis) to separate noise sources from the mixture. For experiments, each noise source signal was synthesized by considering the features such as machinery tonal components and propeller tonal components. And the results of before and after separation were compared by using LOFAR (Low Frequency Analysis and Recording), DEMON (Detection Envelope Modulation On Noise) analysis.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.19-28
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• 2024

This paper proposes a method to improve the performance of ship identification through lofargram analysis of ship noise by applying the Hough Transform to a Convolutional Neural Network (CNN) model. When processing the signals received by a passive sonar, the time-frequency domain representation known as lofargram is generated. The machinery noise radiated by ships appears as tonal signals on the lofargram, and the class of the ship can be specified by analyzing it. However, analyzing lofargram is a specialized and time-consuming task performed by well-trained analysts. Additionally, the analysis for target identification is very challenging because the lofargram also displays various background noises due to the characteristics of the underwater environment. To address this issue, the Hough Transform is applied to the lofargram to add lines, thereby emphasizing the tonal signals. As a result of identification using CNN models on both the original lofargrams and the lofargrams with Hough transform, it is shown that the application of the Hough transform improves lofargram identification performance, as indicated by increased accuracy and macro F1 scores for three different CNN models.

• Journal of Music and Human Behavior
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• v.13 no.2
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• pp.67-83
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• 2016

This study investigated the tonal characteristics in Korean emotion words by analyzing the pitch patterns transformed from word utterance. Participants were 30 women, ages 19-23. Each participant was instructed to talk about their emotional experiences using 4-syllable target words. A total of 180 utterances were analyzed in terms of the frequency of each syllable using the Praat. The data were transformed into meantones based on the semi-tone scale. When emotion words were used in the middle of a sentence, the pitch pattern was transformed to A3-A3-G3-G3 for '즐거워서(joyful)', C4-D4-B3-A3 for '행복해서(happy)', G3-A3-G3-G3 for '억울해서(resentful)', A3-A3-G3-A3 for '불안해서(anxious)', and C4-C4-A3-G3 for '침울해서(frustrated)'. When the emotion words were used at the end of a sentence, the pitch pattern was transformed to G4-G4-F4-F4 for '즐거워요(joyful)', D4-D4-A3-G3 for '행복해요(happy)', G3-G3-G3-A3 and F3-G3-E3-D3 for '억울해요(resentful)', A3-G3-F3-F3 for '불안해요(anxious)', and A3-A3-F3-F3 for '침울해요(frustrated)'. These results indicate the differences in pitch patterns depending on the conveyed emotions and the position of words in a sentence. This study presents the baseline data on the tonal characteristics of emotion words, thereby suggesting how pitch patterns could be utilized when creating a melody during songwriting for emotional expression.

• Speech Sciences
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• v.15 no.1
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• pp.25-36
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• 2008

Language transfer means that the speaker's first language or previously acquired language influences on the production of the target language. This study aims at examining if there is native language influence on the production of English intonation by Korean speakers. The pitch accent patterns and the values of duration, F0, and intensity of the stressed vowel of the word with emphatic accent in the sentence produced by Korean speakers are compared to those of American English speakers. The results show that when the word receives emphatic accent in the sentence, American English speakers put H* accent on the stressed syllable of the word, but Korean speakers mostly assign high pitch on the last syllable of the word and have LH tonal pattern despite the fact that primary stress does not come on the last syllable within a word. In addition, comparison of the values of duration, F0, and intensity of the stressed vowel of the word with emphatic accent to those of the word with unmarked neutral accent shows that Korean speakers do not realize the intonation of the accented word appropriately because the values decrease even though the word has emphatic accent. This study finds out that there are differences in the production of English intonation of the word with emphatic accent between native speakers of English and Korean speakers, and that there is negative transfer of Korean intonation pattern to the production of English intonation by Korean speakers.