2. On the Wave Forms of Articulate Sounds
Fleeming Jenkin, James Alfred Ewing · Proceedings of the Royal Society of Edinburgh · 1878
In this paper the authors gave a preliminary account of experiments made with the help of the phonograph exhibited at the last meeting. The following results have been obtained:— 1. The vowel sounds can be produced by maintaining the relative pitch of the simple tones of which they are composed constant, although the absolute pitch of those simple tones may vary greatly.