AWGN and impulsive noise removal by turbo audio enhancement technique

This paper gives a performance comparison of turbo method of audio signal enhancement with Dual Resonance Non Linear (DRNL) and Signal Dependent Rank Order Mean(SD-ROM). The salient feature of the work is to explore the usage of turbo method for enhancement of signals like vowels and consonants which was not done earlier for this method. Vowels and consonants being the basics of any language, give a different dimension to this work. From the comparison it can be decided which audio signal enhancement technique can be most useful for the signal processing part of the cochlear implant. Due to the iterative nature of turbo method, it gives better signal enhancement. The results have been compiled for sounds corrupted by different noises namely AWGN and impulsive noise. Enhancement is evaluated based on the correlation coefficient, Log Spectral Distortion (LSD), Segmental Signal to Noise Ratio (SSNR) and Mean Square Error (MSE) between the clean signal and the processed signal. Simulation results confirm that, turbo helps in better enhancement for signals corrupted by AWGN. Turbo method provides signal enhancement for impulsive noise but SD-ROM performs better for impulsive noise. DRNL contributes in signal enhancement not as a standalone filter but when used in combination to form turbo.