Implementation of Spectral Subtraction Using Sub-band Filtering in DSP C6748 Processor for Enhancing Speech Signal

Implementation of novel algorithms on Digital Signal Processing [DSP] processor to extract the speech signal from a noisy signal is always of immense interest. Speech signals are usually complex that requires processing of signal in short frames, and thus DSP processors are widely used to process the speech signals in mobile phones. The performance of these devices is comparatively very well in noisy conditions, as compared with traditional processors. The speech signal is degraded by either echo or background noise and as a result, there exists a requirement of digital voice processor for human–machine interfaces. The chief objective of speech enhancement algorithms is to improve the performance of voice communication devices by boosting the speech quality and increasing the intelligibility of voice signal. Popular speech enhancement algorithms rely on frequency domain approaches to estimate the spectral density of noise. This paper proposes a method of assessment, wherein frequency components of noisy speech signal are filtered out using multiband filters. The multiband filters are developed in C6748 DSP processor. Experimental results demonstrate an improved Signal to Noise Ratio [SNR] with fewer computations.