Report Number: CS-TR-72-307
Institution: Stanford University, Department of Computer Science
Title: Hadamard transform for speech wave analysis.
Author: Tanaka, Hozumi
Date: August 1972
Abstract: Two methods of speech wave analysis using the Hadamard transform are discussed. The first method is a direct application of the Hadamard transform for speech waves. The reason this method yields poor results is discussed. The second method is the application of the Hadamard transform to a log-magnitude frequency spectrum. After the application of the Fourier transform the Hadamard transform is applied to detect a pitch period or to get a smoothed spectrum. This method shows some positive aspects of the Hadamard transform for the analysis of a speech wave with regard to the reduction of processing time required for smoothing, but at the cost of precision. A formant tracking program for voiced speech is implemented by using this method and an edge following technique used in scene analysis.
http://i.stanford.edu/pub/cstr/reports/cs/tr/72/307/CS-TR-72-307.pdf