Statistical Modeling for Suppression of Late Reverberation with Inverse Filtering for Early Reflections

Reverberation has two pronounced components i.e. early reflections and late reverberations. A two stage algorithm was applied to tackle each reverberation module separately with an assumption of noise free environment. In the first stage of algorithm, inverse filter was estimated to reduce early reflections while the second stage predicted the late reverberation by means of long term multi-step linear prediction, after which the late reverberation were reduced through spectral subtraction. The two physical variables i.e. reverberation time and signal to noise ratio were used for quantification of reverberant and de-reverberant speech. Proposed algorithm was compared with another recent algorithm using six speech utterances and altered reverberation conditions. Significant improvement was shown by proposed algorithm.