Linear predictive method with low-frequency emphasis

An all-pole modeling technique, Linear Prediction with Lowfrequency Emphasis (LPLE), which emphasizes the lower frequency range of speech, is presented. The method is based on first interpreting conventional linear predictive (LP) analyses of successive prediction orders with parallel structures using the concept of symmetric linear prediction. In these implementations, symmetric linear prediction is preceded by simple pre-filters, which are of either low or high frequency characteristics. Combining those symmetric linear predictors that are not preceded by high-frequency pre-filters yields the LPLE predictor. It is proved that the all-pole filters computed by LPLE are always stable. The results show that the method is well-suited when low-order all-pole models with improved modeling of the lowest formants are needed.