360 ILLINOIS STATE ACADEMY OF SCIENCE 



known to the subject during the remainder of the day's 

 period of experiments. Notes were compared after each 

 reading of the four sentences. 



After two weeks — eight sessions — the subject had at- 

 tained an average accuracy of approximately 70% on 

 the four sentences, each of which was presented 50 times. 

 The fourth sentence he recognized in 86% of cases. It 

 began to be apparent to the subject, however, that up 

 to this time his criteria of judgment were tempo, em- 

 phasis, number of syllables in a sentence — not the qual- 

 ity of the stimulations. We therefore framed new sen- 

 tences, using the old words, to test the question whether 

 any more intrinsic quality of the- words was beginning. 

 The result was disappointing. Previous practice had 

 given the subject no noticeable advantage in learning 

 the new word groupings. 



The subject then began holding the receiver with the 

 aperture disclosing the diaphragm toward the palm. In 

 this case the vibration of the diaphragm is conducted 

 through a cushion of air to the palm and the tactual area 

 stimulated is less restricted than in the earlier practice. 

 By this method, in six sittings the subject attained a 

 confident mastery of the four original sentences and the 

 new ones. These trials carried us up to the end of the 

 first week in the present month. 



Up to that time we had drawn the conclusion that suc- 

 cess in the interpretation of tactual stimuli arising from 

 oral speech will depend upon the stimulation of a fairly 

 wide area or pattern of tactual organs. 



On December 10, we began practice upon the long 

 vowel sounds and continued through the 11th and 12th. 

 We spent approximately one hour on each of these days 

 at drill alone. The order of presentation was always 

 known to the subject, and in the course of every period 

 each vowel was presented 30 times, or 90 times during 

 the three days. Our method of procedure from the 13th 

 to the 19th, inclusive, was as follows : 



(1) The experimenter recited the vowels five times 

 in a known order. 



(2) He recited 15 series of unknown order, 10 in each 

 series -(each vowel occurring twice), the subject writing 



