Dimension and structure of the speech space

Abstract

The paper presents evidence to support its claim that the space of trajectories of speech exists and may be approximated by a fourdimensional manifold which is nonlinearly embedded in both a space of LPC coefficients and also in a filter bank space. It also investigates the possibility that there are different dimensions for different phonetic categories, but finds no evidence to support this hypothesis. The dimension is of interest since it is the smallest number of independent parameters needed to specify speech.