Volume 1
A text-book of experimental psychology : with laboratory exercises / by Charles S. Myers.
- Charles Samuel Myers
- Date:
- 1911
Licence: Public Domain Mark
Credit: A text-book of experimental psychology : with laboratory exercises / by Charles S. Myers. Source: Wellcome Collection.
50/370 page 30
![doubtless of extreme importance. For every variation in time, loudness, or pitch which the fundamental tones of an instru¬ ment undergo must be similarly shared by their overtones. This provides a means of allotting the overtones to their proper fundamental tones.] [The Threshold of Intensity.—In order that a tone or a noise may be heard, the intensity of the stimulus must not fall below a limiting or Timinal’ value. The value of this ‘limen5 or Threshold’ varies according to the nature of the sound, the simultaneous presence of other sounds, the acuity of the subject’s hearing, and the method of estimating the threshold. We shall refer again to these conditions when we come to treat of sensory acuity and attention (Chapters XVIII. and XXV.). If, on the other hand, the loudness of the purest obtainable tone be too great,—that is, if the degree of displacement of the vibrating particles from equilibrium be too great relatively to the magnitude of the force that displaces them,—overtones are produced and the tone no longer preserves its original purity. There is a general tendency for the pitch of loud sounds to appear too high, and conversely for the pitch of faint sounds to appear too low. This illusion is partly due to the change of timbre (page 26) arising from differences in the ratio of the fundamental tone to the overtones. It is, however, doubtless also connected with the greater sensory intensity of high tones as compared with low tones (page 33). Before a sound stimulus produces a sensation, it has to overcome what we may describe as the inertia of the auditory apparatus. If we place the ends of a rubber tube one in either ear, and if we gently rest a very weakly vibrating tuning-fork, preferably of low pitch, on the mid-point of the tube, the tone will at first be inaudible, will later be heard, and will then gradually increase in loudness, the sensation reaching its maximum after one or two seconds. The time thus spent in evoking an auditory sensation is in part due to changes produced in the inner ear, in the auditory nerves, and in the cerebral centres with which the latter directly or](https://iiif.wellcomecollection.org/image/b3135984x_0001_0050.jp2/full/800%2C/0/default.jpg)
