For about seven years I have been, engaged upon the investigation of the impressions made by vowel sounds on phonograph cylinders.
The close accordance of my results with those of Prof. L. Hermann of Königsberg and Dr Hugo Pipping of Helsingfors, though obtained by widely different methods, showed, 1st, that the method by which I obtained my results, although much simpler and easier to manage than those of the above-mentioned investigators, yields, nevertheless, very satisfactory results; and 2nd, that the same vowel sounds are formed almost exactly in the same manner by persons of different age, sex, and nationality.
In the only scientific paper which, till now, I have published on this subject, in 1891, only the vowel a (as in hard) was treated in a somewhat elaborate manner, but since then I have applied my method to other vowels as well.
As I have altered my method of research a little in the course of time, it may be useful to give a somewhat detailed description of my present mode of procedure.