• Speech Sciences
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• v.8 no.2
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• pp.73-81
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• 2001

In this paper, we focus on the real time implementation of the single channel adaptive noise canceller(ANC) by using TMS320C30 EVM board. The implemented single channel adaptive noise canceller is based on a reference paper [1] in which it is simulated by using the recursive average magnitude difference function(AMDF) to get a properly delayed input speech on a sample basis as a reference signal and normalized least mean square(NLMS) algorithm. To certify results of the real time implementation, we measured the processing time of the ANC and enhancement ratio according to various signalto-noise ratios(SNRs). Experimental results demonstrate that the processing time of the speech signal of 32ms length with delay estimation of every 10 samples is about 26.3 ms, and almost the same performance as given in [1] is obtained with the implemented system.

• Journal of Korea Multimedia Society
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• v.13 no.7
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• pp.973-982
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• 2010

In this paper, we proposed the single-channel adaptive noise canceller for the enhancement of heart sound (HS) in the auscultation signal. In case of either normal or emergency, a HS diagnosis is difficult due to the various signal source in the chest. Therefore, the HS enhancement is necessary. The conventional active noise canceller(ANC) has two channel, main signal and reference signal. For signal channel, the reference signal in ANC was generated by the proposed HS analyser and BS-Gate based on the characteristic of HS. This reference signal is suitable to the ANC condition. Experimental data were acquisited from MP36, SS30L in BIOPAC Inc., By the experiment, we confirmed that the proposed single-channel ANC was efficient for HS enhancement. And by the comparison with active linear enhancement, it was validate that the proposed ANC is not affected by the variation of a heartbeat.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.11-14
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• 2000

본 논문에서는 재귀적 지연추정기를 갖는 적응여파기를 이용하여 음성신호에 내재한 배경잡음을 제거하는 단일입력 적응잡음제거기를 TMS320C30 EVM 보드에서 실시간 구현하였다. 이를 위하여 샘플시간마다 지연정보를 구할 수 있는 재귀적 평균 절대차 함수를 사용하고, 정규화 된 최소평균자승(NLMS: Normalized Least Mean Square) 알고리듬을 사용하는 단일입력 잡음제거 시스템을 시뮬레이션한 (1)의 내용을 EVM 보드에 구현하였다. 그리고, (1)과 동일한 방법으로 백색 가우시안 잡음에 의해 왜곡된 음성에 대하여 SNR(Signal-to-Noise Ratio)에 따른 잡음제거 실험을 하였으며, EVM 보드에서의 실험결과를 (1)의 시뮬레이션 결과와 비교/검토하였다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.1
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• pp.18-25
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• 2018

In this paper, we present a low-power implementation of the multi-channel hearing aid system using a general-purpose DSP chip. The system includes an acoustic amplification algorithm based on Wide Dynamic Range Compression (WDRC), an adaptive howling canceller, and a single-channel noise reduction algorithm. To achieve a low-power implementation, each algorithm is re-constructed in forms of integer program, and the integer program is converted to the assembly program using BelaSigna(R) 250 instructions. Through experiments using the implementation system, the performance of each processing algorithm was confirmed in real-time. Also, the clock of the implementation system was measured, and it was confirmed that the entire signal processing blocks can be performed in real time at about 7.02MHz system clock.