• Title/Summary/Keyword: 캡스트럼 포락선

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Spectral Modeling of Haegeum Using Cepstral Analysis (캡스트럼 분석을 이용한 해금의 스펙트럼 모델링)

  • Hong, Yeon-Woo;Kang, Myeong-Su;Cho, Sang-Jin;Kim, Jong-Myon;Lee, Jung-Chul;Chong, Ui-Pil
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.4
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    • pp.243-250
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    • 2010
  • This paper proposes a spectral modeling of Korean traditional instrument, Haegeum, using cepstral analysis to naturally describe Haegeum sounds varying with time. To get a precise result of cepstral analysis, we set the frame size to 3 periods of input signal and more cepstral coefficients are used to extract formants. The performance is enhanced by flexibly controlling the cutoff frequency of bandpass filter depending on the resonances in the synthesis process of sinusoidal components and the deleting peaks remained in the residual signal. To detect the change of pitch, we divide the input frames into silence, attack, and sustain region and determine which region the current frame is involved in. Then, the proposed method readjusts the frame size according to the fundamental frequency in the case of the current frame is in attack region and corrects the extraction errors of the fundamental frequency for the frames in sustain region. With these processes, the synthesized sounds are much more similar to the originals. The evaluation result through the listening test by a Haegeum player says that the synthesized sounds are almost similar to originals (96~100 % similar to the original sounds).

Formant Synthesis of Haegeum Sounds Using Cepstral Envelope (캡스트럼 포락선을 이용한 해금 소리의 포만트 합성)

  • Hong, Yeon-Woo;Cho, Sang-Jin;Kim, Jong-Myon;Chong, Ui-Pil
    • The Journal of the Acoustical Society of Korea
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    • v.28 no.6
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    • pp.526-533
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    • 2009
  • This paper proposes a formant synthesis method of Haegeum sounds using cepstral envelope for spectral modeling. Spectral modeling synthesis (SMS) is a technique that models time-varying spectra as a combination of sinusoids (the "deterministic" part), and a time-varying filtered noise component (the "stochastic" part). SMS is appropriate for synthesizing sounds of string and wind instruments whose harmonics are evenly distributed over whole frequency band. Formants extracted from cepstral envelope are parameterized for synthesis of sinusoids. A resonator by Impulse Invariant Transform (IIT) is applied to synthesize sinusoids and the results are bandpass filtered to adjust magnitude. The noise is calculated by first generating the sinusoids with formant synthesis, subtracting them from the original sound, and then removing some harmonics remained. Linear interpolation is used to model noise. The synthesized sounds are made by summing sinusoids, which are shown to be similar to the original Haegeum sounds.