... 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 ... signal and additive Gaussian noise, the observation pdf of the noisy signal is also Gaussian. Hence, the state observation pdfs of the signal model can be modified to account for the additive noise...