Journal of the Institute of Electronics Engineers of Korea SC (전자공학회논문지SC)

The Institute of Electronics and Information Engineers (대한전자공학회)
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A feedback cancellation algorithm with time delay and time-varying decorrelation filter for digital hearing aid

시간 지연과 시변 상관성 제거 필터를 이용한 디지털보청기용 궤환제거 알고리즘

  • Lee, Sang-Min (Division of Bionics and Bioinformatics, Chonbuk National University) ;
  • Park, Young (Computer. Telecommunicatin Engineering Division) ;
  • Jung, Se-Young (Dept. of Biomedical Engineering, Hanyang University) ;
  • Kim, In-Young (Dept. of Biomedical Engineering, Hanyang University) ;
  • Kim, Sun-I (Dept. of Biomedical Engineering, Hanyang University)
  • Published : 2005.07.01
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Abstract

In digital hearing aid system, one of the main problems is acoustic feedback which is known as howling because of miniaturization md high-gain amplification. In this paper, we proposed a feedback cancellation algorithm for hearing aid using time delay and time-varying decorrelation filter. The proposed algorithm has a kind of adaptive filter structure, which is combined with time delay and time-varying decorrelation filter to improve feedback cancellation. An all pass filter was implemented as the time-varying decorrelation filter using low frequency modulator. From the result of computer simulation, it is verified that the proposed algorithm has good ability to cancel feedback.

디지털 보청기 시스템에서는 소형화, 고이득 증폭이 요구되는데 이로 인한 문제점 중의 하나가 하울링(howling)이라는 음향의 궤환이다. 본 논문에서는 시간지연과 시변 상관성 제거 필터를 이용하여 보청기에서 사용 가능한 음향 궤환 제거 알고리즘을 제안하였다. 제안한 알고리즘은 적응형 필터 구조를 기본으로 음향 궤환 신호 제거 효과를 증대시키기 위해 시간 지연과 상관성 제거 필터를 삽입하였다. 상관성 제거 필터로 사용된 전대역 통과 필터는 저주파 변조기를 이용하여 시변 특성을 갖도록 구현 하였다. 컴퓨터 시뮬레이션 결과를 통하여 제안한 알고리즘의 궤환 제거 특성이 우수함을 확인하였다.

Keywords

References

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