Some Remarks on the Modern Status of Auditory Theory

Abstract

A discussion is made of two lines of evidence that bear upon the problem of the relative importance of place and frequency principles in auditory theory. The first line of evidence has to do with the relation between pitch discrimination and the degree of specificity of action in the cochlea and brings us to an evaluation of the principle of maximum stimulation. A consideration of loudness discrimination data discloses a serious limitation on our ability to appreciate the point of maximum in the cochlear activity and, in general, to make use of a spatial pattern. We must conclude that for the low tones whose patterns are broad the place principle contributes little or nothing to pitch discrimination, and the frequency principle has to serve this function alone. A study of the evolution of the ear brings out still more clearly the relative roles of place and frequency principles. Hearing in some degree is present throughout the vertebrate series, and even the lowest forms have frequency ranges of several octaves and exhibit a fair degree of tonal discrimination. Yet, these lower forms possess an ear of exceeding simplicity, an otic sac in which there is little evidence of mechanical differentiation. It follows that these primitive ears must operate as frequency receptors, with ranges and discriminative abilities that depend simply upon the patterns of impulses conveyed by the auditory nerve. It appears, therefore, that in the history of the ear the frequency principle came first as the basis of tonal reception, and only sometime later in the course of evolutionary development was it joined by the place principle.