The Phonograph

Abstract

SINCE writing my former letter on the phonograph (NATURE, vol. xvii. p. 485) I have had the advantage of seeing some of the work that Prof. Fleeming Jenkin is doing with his own instrument, which must, I think, be more sensitive than the one I examined. This work convinces me that the phonograph has already risen beyond the rank of lecture illustrations and philosophical toys, to which I assigned it in my last, and that it promises to lay some permanent foundations for the more accurate investigation of the nature of speech sounds. Prof. Fleeming Jenkin, by a most ingenious arrangement, which I must leave him to describe in his paper to the Royal Society of Edinburgh, obtains vertical sections of the impressions made on the tin-foil by the point of the phonograph, magnified 400 diameters. Some of these original tracings I had the pleasure of seeing yesterday, and they are full of interest. I have termed them “speech curves.” They differ considerably from the phonautographic speech-curves of Léon Scott and Koenig, which only succeeded with the vowels, and from the logographic speech-curves of Mr. Barlow, which only succeeded with the consonants, in so much as they succeed with both. In such a word as tah, for example, intoned rather than sung, but not simply spoken, as the vowel would otherwise not last long enough for subsequent study, we have first the “preparation,” in which the curve gradually, but irregularly, rises, then the “attack”, where there is generally a bold serrated precipice, with numerous rather sudden valleys; next the “glide” where there is a perfect tumult of curvatures arising from the passage of voice through a continually changing resonance chamber, producing a rapidly and continuously changeing but indistinct series of vowel sounds, which gradually settle down into the “vowel” proper. In the vowel, if well intoned, the curve remains constant for a considerable number of periods, beautifully reproducing itself, but, as the intoner becomes exhausted, “vanishing” away gradually to silence, the distinctive peculiarities of the curve disappearing one by one, till a dead level is again reached.