디지털 보청기에서 마이크로폰 어레이를 이용한 잡음제거

In this paper, a noise cancellation-method using microphone array for digital hearing aids is proposed. The microphone array is located around the ear of a dummy. Speech sound is generated from the forward speaker positioned in the front of the dummy and noise sound is generated from the backward speaker. The speech and noise are mixed in the air space and entered into the microphones. VAD(voice activity detector) and ANC(adaptive noise cancellation) methods were used to eliminate noise in the sound of the microphones. 10 two-syllable words and 4 sentences were used for speech signals. Babble and car interior noise were used for noise signals. The performance of the proposed algorithm was evaluated by SNR(signal-to-noise ratio) and PESQ-MOS(perceptual evaluation of speech quality-mean opinion score). In babble noise condition, SNR was improved as much as 7.963±1.3620㏈ and 3.968±0.6659㏈ for words and sentences respectively. In the case of car interior noise, SNR was improved as 10.512±2.0665㏈ and 6.000±1.7642㏈ for words and sentences respectively. PESQ-MOS of the babble noise was improved as much as 0.1722±0.0861 score for words and 0.083±0.0417 score for sentences. And PESQ-MOS of the car interior noise was improved as 0.2661±0.0335 score and 0.040±0.0201 score for words and sentences respectively. It is verified that the proposed algorithm has a good performance in noise cancellation of microphone array for digital hearing aids.