Smoothed local adaptation of connectionist systems

ABBOT is the hybrid connectionist hidden Markov model (HMM) large vocabulary continuous speech recognition system developed at Cambridge University Engineering Department. ABBOT makes effective use of the linear input network (LIN) adaptation technique to achieve speaker and channel adaptation. Although the LIN is effective at adapting to new speakers or a new environment (e.g. a different microphone), the transform is global over the input space. In this paper we describe a technique by which the transform may be made locally linear over different regions of the input space. The local linear transforms are combined by an additional network using a non-linear transform. This scheme falls naturally into the mixtures of experts framework