Inverse lattice filtering of speech with adapted non-uniform delays

A particular form of constraint is incorporated to Linear Prediction lattice lter models in the form of unequal-length delays. This constraint amounts to reducing the number of intrinsic degrees of freedom de ned by the re ection coeÆcients without modifying the LPC order of the corresponding transfer function. It can be optimized by a simple exhaustive search scheme. Preliminary results show that the prediction error is slightly decreased with respect to a conventional predictor using the same number of re ection coeÆcients.