A Course in Experimental Psychology

n to musical tones will often discover the presence of accompanying noises. Wundt, 3te Aufl., I., 420; 4te Aufl., I., 447 f; Stumpf, II., 497- 515; Brucke; Exner; Mach, B, 117. 66. Silence. When circumstances promise absence of external sounds, notice that many are still present and distinct, though faintly heard. Notice also the pitch and changing character of the subjective sounds to be heard. Our nearest approach to the experience of absolute stillness is ihis mass of faint inner and outer sensations. Preyer, A, 67-72; Stumpf, I., 380 fi. Single And Successive Tones. 67. Highest Tones. With the apparatus at hand for the purpose, find what is the 'highest audible tone ; i. e., if the cylinders are used, the shortest cylinder which still gives a ringing sound when struck with the hammer, or if the whistle is used, the closest position of the plunger at which a tone can still be heard beside the rush of air. If a number of persons are tested, it is not improbable that some will yet hear the tone after it has become inaudible for the rest. Same references as Ex. 68. 68. Lowest Tones. If low-pitched tuning-forks or other vibrators are at hand, find what is the slowest rate of vibration that can yet be perceived as a tone. In some physiological laboratories electric tuning-forks or interrupters may be found that have vibration rates of twenty-five per second. Low tones can be heard from these, though they have manyovertones. The latter can be partly...