A preprocessing filter for enhancing LPC analysis/Synthesis of noisy speech

The goal of this study was to develop an effective and computationally inexpensive method of enhancing the linear prediction analysis/synthesis of noisy speech. To this end, a preprocessing filter has been proposed that is capable of perfectly removing the "expected" noise signal when the input speech spectrum is closely approximated by the noisy speech spectrum. The proposed filter has been evaluated by the linear prediction distance measure, perceptual listening, and spectrograms. This evaluation has demonstrated the effectiveness of the filter for broadband noise removal. The filter has also been implemented as a preprocessing filter in a real time LPC system. The total processing time for the filtering is only 2.6 msec per 22.5 msec frame. In this system, the LPC analysis and synthesis takes a combined time of 13 msec.