594 



SCIENCE 



[N. S. Vol. XLHI. No. 1113 



other dots move and tend to blur. The row 

 whieli stands still, therefore, points to a num- 

 ber on the scale which designates the pitch of 

 the tone. The screen contains a sufficient 

 number of rows of dots to cover exactly one 

 octave. Tones above or below this octave are 

 read on this same screen by multiples. 



To see the pitch of the tone, one has, there- 

 fore, only to see the nmnber of the line that 

 stands still. The tone may be sung or played 

 under natural conditions. Indeed, one may 

 register the tone from any distant point with 

 which there are telephone connections. 



The instrument is operated electrically and 

 will run indefinitely without any care or dis- 

 turbance. This makes the tonoscope a ready 

 and continuously available instrimient in the 

 studio or the laboratory. The speed of the 

 revolving screen is controlled by a tim.ing- 

 fork with which it must keep step, being driven 

 by a synchronous motor. 



In other words, we have here an instrument 

 which will transform the vibrations of voice 

 or instrument to visual configurations on a 

 scale that indicates the actual pitch of any 

 note down to an accuracy of a fraction of a 

 vibration — often less than a hundredth of a 

 tone. Indeed, if we are dealing with a note as 

 constant as that of a tuning-fork or a string, 

 the pitch will be recorded accurately in tenths 

 of a vibration, because fractions of vibrations 

 may be read in terms of the number of dots 

 that pass per second in the slowly moving line. 



There are various graphic methods of record- 

 ing pitch in use, but these are entirely too 

 laborious and cumbersome for practical use. 

 The tonoscope furnishes us the first ready and 

 at the same time reliable and accurate means 

 of registering directly the pitch of a tone as 

 sung, spoken, or played with a musical instru- 

 ment in such form that it can be operated with 

 convenience and safety outside the technical 

 laboratory. 



THE SIGNIFICANCE OF THIS INSTRUMENT FOR THE 

 SCIENCE OF TONES 



The psychology of music on the sensory 

 side has been studied with fruitful success in 

 recent years. But the motor side of the proc- 



ess — the psychology of tone-production and 

 tone-control — is practically unworked and re- 

 mains largely in the realm of mystery chiefly 

 for the want of a measuring instrument. The 

 introduction of a ready means of recording, 

 analyzing and projecting sound vibrations be- 

 fore the eye therefore opens up a most wonder- 

 ful field of research both in pure science and 

 in the art of music. 



IJp to the present time there has been only 

 one tonoscope available, that in the psycholog- 

 ical laboratory of the University of Iowa. 

 This has passed through several stages of im- 

 provement during the last fifteen years; and 

 this single instrument in its various stages of 

 development, in the hands of a small group of 

 investigators, has been a valuable aid in the 

 discovery of interesting facts in the psychol- 

 ogy of music. The scope of the work which 

 has thus been opened up by investigations al- 

 ready undertaken may be illustrated by the 

 naming of the principal problems which have 

 been investigated up to date, to wit : the com- 

 parison of men and women as to ability in 

 singing of true pitch, under a large number of 

 controlled conditions; relative accuracy of 

 pitch within the tonal range, under various 

 conditions; principles involved in the singing 

 of large and small, natural intervals and more 

 artificial intervals ; the effect of the strength of 

 the keynote upon the accuracy of reproduction; 

 the effect of the volume of the voice upon the 

 pitch; the variation of pitch with vowel qual- 

 ity or timber; the correlation of ability to sing 

 in pitch with pitch discrimination, tonal mem- 

 ory, tonal imagery, sense of consonance, mu- 

 sical education, and other factors; the estab- 

 lishment of norms for the measurement of 

 ability to sing in pitch; and the study of the 

 effect of training the ear by the aid of the eye. 

 Some of these are reported by Miles in the 

 article referred to above. Psychological Mono- 

 graph ISTo. 69. The scope of this paper will 

 permit the discussion of only one of these, 

 and for this purpose, the last mentioned may 

 be chosen. 



TRAIinNG THE EAR BY THE AID OP THE EYE 



The practical use of the tonoscope in the 



