The influence of timbre and loudness on the localization of sounds / by Charles S. Myers.

  • Charles Samuel Myers
Date:
[1914?]
Catalogue details

Licence: In copyright

Credit: The influence of timbre and loudness on the localization of sounds / by Charles S. Myers. Source: Wellcome Collection.

    6/22 (page 270)
    composition, were covered on their inner surface with a thick layer of horsehair. The floor, also isolated from the rest of the building, was similarly covered. By this means the reflection of sounds from the walls and floor was reduced to a minimum. The subject sat blindfold in the centre of the room. A sound perimeter (P, c/. also fig. 2) was constructed for these experiments. It consisted essentially in an arm M, silently rotatable about Z by means of the handle L, and carrying a funnel-shaped mouth F, which was connected by a flexible pipe with the sound-producing apparatus in a neighbouring room. The centre about which the arm of the perimeter rotated was always placed over the point midway between the two ear-holes. The perimeter could be turned round the axis A so as to give sounds in the vertical as well as in the horizontal plane. With the perimeter arranged as in fig. 2 the sound could be presented at any point in the median vertical (sagittal) plane, i.e. directly in front of (= 0°), above (= 90° v.) or behind (= 180°) the subject, or at any inter¬ mediate point. The sound could also be presented, as in the arrangement of the perimeter shown in fig. 1, at any point in the horizontal plane at the level of the ears, i.e. directly in front of (= 0°) or behind (= 180°) the subject, or exactly opposite the right or left ear (= 90° h. or 270° h.) or at any intermediate point. The pipe connecting the funnel with the sound-producing apparatus was enveloped with layers of cotton wool and bandages, and passed through a tube in the wall of the sound-proof room to a very wide-mouthed horn H, such as is used in connection with the phonograph when heard in large halls. Before this horn were arranged four of Stern’s tone-variators, Vi, V2, V3, V4, blown by wind from a hydraulically worked organ bellows. These tone-variators, one of which, Vi, was unenclosed, produce relatively pure (overtone-free) tones ; they are essentially bottle whistles, each consisting of a mouthpiece fixed over a metal air-containing cylinder. The pitch of the note depends on the height and circumference of the cylinder, the base of each cylinder being movable so as to adjust the pitch accurately. The first or largest tone-variator was arranged to emit a (fundamental) tone of 215 vibrations per second. The second variator gave the first overtone, the third gave the second, and the fourth gave the third overtone, of this fundamental, i.e. they emitted tones of 430, 645, and 860 vibrations per second respectively. In order to reduce and to vary at will the loudness of these overtones, the three corresponding variators, V2, V3, V4, were each enclosed in a wooden box, open at one end.. The open end of each box could be more or less completely closed by means of an adjustable slide, thus allowing the intensity of the overtones (and hence the timbre of the