RESEARCH
Acoustic & Speech
Investigates various Speech signal processing schemes for acoustic modeling so that more robust speech recognition can be achieved. Our aim is to perform the state-of-art research providing effective means for achieving:
Acoustic echo cancellation
작성자 관리자
날짜 2021-04-08 21:25:19
조회수 305
Contents
1.1 What is the Acoustic echo : Acoustic echo arises when sound from a loudspeaker of a hands-free, teleconference and speech recognition system is picked up by the microphone as an undesired signal in the same room.
- Hands-free or teleconference : When a man communicate with a woman using a hands-free, man's voice from a woman's loudspeaker can be the input of the woman's microphone, therefore a man hear the returned his echo voice.
- Speech Recognition : When a telematics or intelligent robot generate the sound (voice, music, etc.), the returned echo signal (not user's voice) cause the wrong speech recognition result.
2.1 Adaptive filter for acoustic echo cancellation
-
Normalized Least Mean Square (NLMS) algorithm.
-
Decorrelated NLMS, Affine algorithm. etc.
2.2 Double talk detector
- Detect the user's voice and halt the adaptive filter's update
- Algorithms : cross-correlation technique, energy based technique, variations impulse response based technique, etc.
2.3 Integration system with noise reduction algorithm
- Single channel based noise reduction : spectral subtraction, wiener filter, OM-LSA, etc.
- Multi-channel based noise reduction : beamforming, eigenvalue decomposition.
Echo cancellation in hands-free communication
Speech recognition with echo cancellation
댓글 (0)
등록된 댓글이 없습니다.
작성 권한이 없습니다.