Abstract: We have designed a novel method of noise reduction for dual-microphone mobile phones. The method is based on a set (bank) of target-cancellation filters derived in a noise-free situation for different possible positions of the phone with respect to the speaker mouth. The set of the cancellation filters is used to accurately estimate the noise of the environment, which is then subtracted from the recorded signal. Experiments with recorded data show a good performance and low complexity of the system, making it possible for an integration into mobile communication devices.
Experiments: We compare the proposed method with the state-of-the-art method based on Power Level Differences (PLD) by Jeub et al. . PLD assumes that the secondary microphone is placed on the rear side of the mobile. Our method can be designed for any microphone arrangement. In comparison to PLD, it achieves better perceptual quality and is able to work in difficult scenarios where SNR is lower than 0 dB. See results of experiments with a model of a dual-channel mobile phone with switchable microphone arrangements (front-front and front-rear).
-  Z. Koldovský, P. Tichavský, D. Botka, “Noise Reduction in Dual-Microphone Mobile Phones Using A Bank of Pre-Measured Target-Cancellation Filters,” Proc. of ICASSP 2013, pp. 679-683, Vancouver, Canada, May 2013. (here)
-  M. Jeub, C. Herglotz, C. M. Nelke, C. Beaugeant and P. Vary, “Noise Reduction for Dual-Microphone Mobile Phones Exploiting Power Level Differences, “, Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP), pp. 1693–1696, Kyoto, Japan, Mar. 2012.