... signal and the noise HMMs maybe expressed as ()=η,,,maxmaxargnoisesignalsignal noise signalMssYsYssfMAP (5.46) and ()=η,,,maxmaxargnoisesignalnoisesignal noise MssYsYssfMAP ... filtering and the spectral subtraction methods described in Chapters 6 and 11) or by combining the noise and the signal models to model the noisy Signal and Noise Model Combination and Decomposition ... in the presence of noise, since noise causes a mismatch between the clean HMMs and the noisy signals. The noise- induced mismatch can be reduced: either by filtering the noise from the signal...