Improved LPC Vocoder using Instantaneous Pitch Estimation Method

Speech coding is an important aspect of modern telecommunications. Speech coding algorithms have different dimensions of performance. Among them, speech quality and average bit rate are the most important performance aspects. The primary objective of speech coding is to represent the speech signal with the fewest number of bits, while maintaining a sufficient level of quality of the retrieved or synthesized speech and with reasonable computational complexity. The quality of the retrieved speech depends on how well the features of the speech are being extracted. Among the various features, Pitch is the prime parameter since human hearing system is more sensitive in discriminating the frequency variations. A new method for estimation of instantaneous pitch of speech signal has been proposed, and this method is applied in the LPC vocoder. Results indicate that the synthesized speech signal provides better quality when compared to the conventional method.