A low-complexity sound recording system for elderly security in home-care system

This work presents a sound recording system for elderly security with low-complexity computation. To reduce the time complexity, the proposed system utilizes the discrete wavelet transform (DWT) with only multiplication to replace the traditional modified discrete cosine transform (MDCT). Such a transform can effectively reduce the computational time of proposed system. For recording the zeroes of the wavelet coefficients, an efficient zero recording algorithm is proposed. The proposed algorithm uses different encoding mode and corresponding bit data structure to further improve compression performance. The experimental results show that the proposed system can achieve about 33-fold improvement of the computation speed compared with the baseline, with also the similar rate-distortion performance. Such results indicate that the proposed system is superior to the baseline work to further be applied in low-end sound recording device for home-care services.