Residual noise compensation for robust speech recognition in nonstationary noise

We present a model-based noise compensation algorithm for robust speech recognition in nonstationary noisy environments. The effect of noise is split into a stationary part, compensated by parallel model combination, and a time varying residual. The evolution of residual noise parameters is represented by a set of state space models. The state space models are updated by Kalman prediction and the sequential Maximum Likelihood algorithm. Prediction of residual noise parameters from different mixtures are fused, and the fused noise parameters are used to modify linearized likelihood score of each mixture. Noise compensation proceeds in parallel with recognition. Experimental results demonstrate that the proposed algorithm improves recognition performance in highly nonstationary environments, compared with parallel model combination alone.