Research on Speech Codec with Compression using Legendre Polynomials

Speech Codecs have been developed in several forms over the past 30 years and are used in Cellular digital telephony. Based on the throat excitation pulses and mouth cavity filter model, all the methods aim to encode the speech samples without much loss of clarity. The complexity of the methods using codebook searching, filtering and matrix inversion, all need heavy computations, leading to timing constraints. After describing a tutorial elucidating the essentials of the present methods, a different direct method of encoding, suggested by the spherical harmonic oscillator functions of Legendre, is introduced. Its performance and simplicity are such that the same may find its applications soon.