DPCC Analysis: Linear Predictive Coding
signals. This scenario is very inefficient, since most of the signals generated by the human voice are small. Voice quality needs to focus on small signals. To solve this problem, adaptive DPCM is developed.
4. Linear Predictive Coding
Linear Predictive Coding (LPC), a powerful, good quality, low bit rate speech analysis technique for encoding a speech signal. The source filter model used in LPC is also known as the linear predictive coding model. It has two main components LPC analysis (encoding) and LPC synthesis (decoding). The goal of the LPC analysis is to estimate whether the speech signal is voiced or unvoiced, to find the pitch of each frame and to the parameters needed to build the source filter model. These parameters are transmitted …show more content…
Mathematical analysis of LPC
For speech analysis and synthesis a linear predictive coding (LPC) method is based on modeling the vocal tract as a linear all-Pole (IIR) filter, whose system transfer function is: where „p‟ is the number of poles, „ap‟ are the parameters that determine the poles and „G‟ is the filter Gain,. There are two excitation functions to model voiced and unvoiced speech sounds. The output of the random noise generator will generate unvoiced sound by exciting the all-pole filter. On the other hand, by a periodic impulse train a voiced speech is generated by exciting the all pole filter model.
Fig.1: Speech production by LPC Fig. 1. Speech production by LPC.
The fundamental difference between these two voiced and unvoiced speech sounds comes from the way how they are produced. The vocal cords vibrations produce these voiced sounds. The vocal cords vibrate at the rate which determines the pitch of the sound whereas; unvoiced sounds do not depend on the vibration of the vocal cords. By the constriction of vocal tracts the unvoiced sounds are produced. The constrictions of the vocal tract force
S. K. Jagtap/ Procedia Computer Science00 (2015) 000–000 5 air out to produce the unvoiced sounds when the vocal tract is
4. Linear Predictive Coding
Linear Predictive Coding (LPC), a powerful, good quality, low bit rate speech analysis technique for encoding a speech signal. The source filter model used in LPC is also known as the linear predictive coding model. It has two main components LPC analysis (encoding) and LPC synthesis (decoding). The goal of the LPC analysis is to estimate whether the speech signal is voiced or unvoiced, to find the pitch of each frame and to the parameters needed to build the source filter model. These parameters are transmitted …show more content…
Mathematical analysis of LPC
For speech analysis and synthesis a linear predictive coding (LPC) method is based on modeling the vocal tract as a linear all-Pole (IIR) filter, whose system transfer function is: where „p‟ is the number of poles, „ap‟ are the parameters that determine the poles and „G‟ is the filter Gain,. There are two excitation functions to model voiced and unvoiced speech sounds. The output of the random noise generator will generate unvoiced sound by exciting the all-pole filter. On the other hand, by a periodic impulse train a voiced speech is generated by exciting the all pole filter model.
Fig.1: Speech production by LPC Fig. 1. Speech production by LPC.
The fundamental difference between these two voiced and unvoiced speech sounds comes from the way how they are produced. The vocal cords vibrations produce these voiced sounds. The vocal cords vibrate at the rate which determines the pitch of the sound whereas; unvoiced sounds do not depend on the vibration of the vocal cords. By the constriction of vocal tracts the unvoiced sounds are produced. The constrictions of the vocal tract force
S. K. Jagtap/ Procedia Computer Science00 (2015) 000–000 5 air out to produce the unvoiced sounds when the vocal tract is