A few methods have been devised which avoid the difficulties incident to the use of a diaphragm, but they are not applicable to the measurement of rhythm material. The instruments which might be used for recording spoken rhythms are all modifications of two well-known forms of apparatus, the phonautograph and the phonograph. The phonograph record is incised in wax, and presents special difficulties for study. Boeke, however, has studied the wax record under a microscope, with special arrangements for illumination. The work is quite too tedious to permit of its use for material of any length, though it is fairly satisfactory when applied to single vowels. In order to enlarge the record, and at the same time to obtain the curves in the plane of the record surface, Hermann devised an attachment to the phonograph (cf. Marage, loc. citat.) by which the movements of the stylus of the phonograph are magnified by a beam of light and recorded on photographic paper. The measurements of entire words by this method would be as tedious as by Boeke’s.
E.W. Scripture has chosen another type of talking machine from which to obtain transcribed records. The permanent record of the gramophone (which makes a record in the plane of the surface, like the phonautograph) is carefully centered, and a lever attached to a stylus which follows the furrow of the record transcribes the curve on the kymographic drum as the plate is slowly revolved. The method has the advantage of using a record which may be reproduced (i.e. the original gramophone record may be reproduced), and of giving fairly large and well defined curves for study. It is too laborious to be applied to extended research on speech rhythms, and has besides several objections. The investigator is dependent on the manufacturer for his material, which is necessarily limited, and cannot meet the needs of various stages of an investigation. He knows nothing of the conditions under which the record was produced, as to rate, on which time relations depend, as to tone of voice, or as to muscular accompaniments. There are also opportunities for error in the long lever used in the transcription; small errors are necessarily magnified in the final curve, and the reading for intensity (amplitude of the curve) is especially open to such error.
The stylus of such a recording apparatus as is used by the gramophone manufacturers, is subject to certain variations, which may modify the linear measurements (which determine time relations). The recording point is necessarily flexible; when such a flexible point is pressed against the recording surface it is dragged back slightly from its original position by friction with this surface. When the point is writing a curve the conditions are changed, and it sways forward to nearly its original position. This elongates the initial part of the sound curve. This fact is of little importance in the study of a single vowel, for the earlier part of the curve may