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Abstract: Linear predictive coding (LPC) is defined as a digital method for encoding an analog signal in which a particular value is predicted by a linear function of the past values of the signal. Human speech is produced in the vocal tract which can be approximated as a variable diameter tube. The linear predictive coding (LPC) model is based on a mathematical approximation of the vocal tract represented by this tube of a varying diameter. At a particular time, t, the speech sample s(t) is represented as a linear sum of the p previous samples. The most important aspect of LPC is the linear predictive filter which allows the value of the next sample to be determined by a linear combination of previous samples. This paper describes how different parameters of speech signal are extracted for faithful reproduction of speech.
Key Words: Linear Predictive Coding (LPC), voiced sounds, pitch, vocal tract
I. INTRODUCTION
Linear Predictive Coding (LPC) is one of the methods of compression that models the process of speech production[1]. Specifically, LPC models this process as a linear sum of earlier samples using a digital filter inputting an excitement signal Speech coding or compression is usually conducted with the use of voice coders or vocoders. There are two types of voice coders: waveform-following coders and model-base coders. Waveform following coders will exactly reproduce the original speech signal if no quantization errors occur. Model based coders will never exactly reproduce the original speech signal, regardless of the presence of quantization errors, because they use a parametric model of speech production which involves encoding and transmitting the parameters not the signal. Lpc Vocoders are considered model-based coders which means that LPC coding is lossy even if no quantization errors occur. The general algorithm for linear predictive coding involves an analysis or encoding part and a synthesis or decoding part. In the encoding, LPC takes the speech signal in blocks or frames of speech and determines the input signal and the coefficients of the filter that will be capable of reproducing the current block of speech. This...