A Frequency-Dependent Speech Enhancement Methods

The corruption of speech due to presence of additive background noise causes severe difficulties in various communication environments. Most implementations and variations of the basic spectral subtraction technique advocate subtraction of the noise spectrum estimate over the entire speech spectrum. However, real world noise is mostly colored and does not affect the speech signal uniformly over the entire spectrum. This study explores a Multi-Band Spectral Subtraction (MBSS) approach with suitable pre-processing of the speech signal. Speech is processed into N (1 N 8) frequency bands and spectral subtraction is performed independently on each band using band-specific over-subtraction factors.