The Speech Chain

The goal of this course is to give students of speech, hearing, and language sciences, phonetics, and psychology the tools they require in order to quantitatively model speech production and perception. This course is designed to satisfy two specific curricular goals, and one research goal. (1) ECE 598AL satisfies the ASHA Audiology certification requirement for curriculum in the “Physical characteristics and measurement of acoustic stimuli” and the “Principles, methods, and applications of psychoacoustics.” (2) ECE 598AL provides, to linguists, the physical and psychophysical foundations upon which to build future courses and research. (3) In addition to its curricular goals, ECE 598AL is explicitly designed to facilitate inter-disciplinary research by providing a common vocabulary. We will start out by discussing basic acoustics: you will discover that any sound can be represented as the sum of sine waves at different amplitudes, frequencies, and phases. On this basis, you will see how to construct, manipulate, and sequence acoustic filters, including such filters as a pipe organ, a human vocal tract, a reverberant room, the outer ear, and the inner ear. The particular sources and filters used to produce and perceive the sounds of English will be treated in great detail. You will discover that humans are sensitive to something similar to the logarithms of both frequency and amplitude, and that human sensitivity has been formalized in measurement systems such as the decibel, the sone, the Bark, and the mel. By modeling this processing as a series of filters, you will discover quantitative measurements of speech intelligibility, and the ways in which such quantitative models can be used to explain the results of listening experiments and the the distinctive features of language.