Title :
Speech enhancement using nonlinear microphone array with noise adaptive complementary beamforming
Author :
Saruwatari, Hiroshi ; Kajita, Shoji ; Takeda, Kazuya ; Itakura, Fumitada
Author_Institution :
Graduate Sch. of Eng./CIAIR, Nagoya Univ., Japan
Abstract :
This paper describes an improved complementary beamforming microphone array with a new noise adaptation. Complementary beamforming is based on two types of beamformers designed to obtain complementary directivity patterns. In this system, two directivity patterns of the beamformers are adapted to the noise directions so that the expectation values of each noise power spectrum are minimized. Using this technique, we can realize the directional nulls for each noise even when the number of sound sources exceeds that of microphones. To evaluate the effectiveness, speech enhancement experiments are performed based on computer simulations with a two-element array and three sound sources. Compared with the conventional spectral subtraction method cascaded with the adaptive beamformer, it is shown that the proposed array improves the signal-to-noise ratio of degraded speech by more than 6 dB and performs more than 18% better in word recognition rates when the interfering noise is two speakers
Keywords :
acoustic noise; array signal processing; microphones; speech enhancement; speech recognition; complementary directivity patterns; computer simulations; degraded speech; directional nulls; interfering noise; noise adaptive complementary beamforming; noise power spectrum; nonlinear microphone array; signal-to-noise ratio; sound sources; spectral subtraction method; speech enhancement; two-element array; word recognition rates; Acoustic noise; Adaptive arrays; Array signal processing; Computer simulation; Degradation; Microphone arrays; Performance evaluation; Signal to noise ratio; Speech enhancement; Speech recognition;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 2000. ICASSP '00. Proceedings. 2000 IEEE International Conference on
Conference_Location :
Istanbul
Print_ISBN :
0-7803-6293-4
DOI :
10.1109/ICASSP.2000.859143