Adaptive Gain Equalizer for improvement of esophageal speech

The vocal fold modulate the air source from lungs to produce voicing source for speech production. The vocal fold essential part of speech production resides in larynx. The larynx cancer treatment necessitate removal of larynx, in consequences normal speech production destroyed due to no voicing source available. The new voicing source provided artificially or by use of Paryngo-esophageal(PE) segments. The voicing source or residual signal for Esophageal(E) speech uses PE segment, has irregular behavior, and produces degraded quality speech. This paper discussed and evaluated the residual signal or voicing source enhancement of E speech by incorporating speech enhancement method Adaptive Gain Equalizer(AGE), in time-frequency and modulation frequency along with formants modification by Line Spectral Frequencies(LSF) and Linear Predicative Coding(LPC). The system validated by measuring Harmonic to Noise Ratio(HNR) temporally and maximum of 4dB enhancement has been observed in comparison to Kalman filtering based enhancement where enhancement observed maximum of 2dB.