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.

    11/22 page 275
    as I have already mentioned, the position of the auricle is adapted for “ catching ” sounds coming from in front (and in consequence of which our auditory acuity is keener for forward than for rearward sounds). But turning the head alters, too, the timbre of the sounds; a forward sound appears to the ear not only louder than, but also of a different timbre from, the sound placed to the rear.* It is noteworthy, however, that, whereas change in the position of the head while the sound was being heard was remarkably effective in correcting errors of localisation, change in the position of the sound while the head was at rest proved of little or no advantage for such correction. It generally resulted in an interpretation of increased or diminished loudness, or of increased or diminished distance of the sound; less frequently, a movement of the sound was detected, but the direction of the movement was not always correctly given, and the initial error in localisation failed to be corrected by the detected movement of the sound. This difference in effect between what may be conveniently termed “ active ” and “ passive ” change in the position of the sound is of considerable interest in relation to the associated function of the semicircular canals and (in animals) of the movements of the auricle. Two other factors which are conceivably of importance in determining the incidence of sounds, but which were almost wholly eliminated in these experiments, may be briefly mentioned. Of these the influence of expecta¬ tion has been already alluded to on p. 273, and was almost always success¬ fully ruled out by the noiseless movement of the perimeter. On several occasions I expressly asked the subjects if they had any notion of where the sound was coming from, and they generally replied that they had no idea. In everyday life, however, and, perhaps, in many of the experiments other¬ wise conducted, various cues may determine a favourable attitude of expectation in the subject. The remaining factor, the effect of sound reflections from the ceiling, walls, and floor, was prevented by the peculiar construction of the sound-proof room (pp. 268-270). But in everyday life and after brief practice in experiments, conducted under ordinary conditions, there are indications that such reflections are taken into account and thus assist in determining the incidence of the sound.f * It is practically impossible to increase the loudness of a sound (i.e. the intensity of the fundamental and its overtones) without altering its timbre (the relative intensity of the fundamental and its overtones). Even if this could be physically realised, the varying position of the peculiarly formed auricle relatively to the sound may be expected to influence the ease with which it takes up the different overtones contained in the sound. t Since writing this, I have examined two subjects, first in an ordinary room, and later (after a rest) in the sound-proof room, using the perimeter with an attached
    digitised image 1
    digitised image 2
    digitised image 3