Modifications to nonlinear processing for recruitment of loudness

The time-varying frequency-dependent processing (TVFD) [J. C. Rutledge and M. A. Clements, Proc. IEEE ICASSP, 3641–3644 (1991)] was designed to adjust to changing speech input on both time and frequency basis. Due to inherent problems with the processing technique, some spectral smearing occurs [J. Acoust. Soc. Am. 89, 1974 (A) (1991)]. The processing has been modified to maintain the time-varying frequency-dependent nature, but reduces the smearing effect. A sinusoidal speech model is used with the compensation processing. Appropriate gains for the sinusoid amplitudes are calculated every 5 ms. In the modified processing scheme, the gain determined for the largest peak in each frequency band is applied to all components in that band. This maintains the relative amplitude ratio between neighboring peaks in the frequency spectrum. The compensation algorithm is presented here along with preliminary performance results based on the objective measures described in another paper at this meeting.