NA TURE 



[July i, 1897 



When human voice sounds are produced in singing, especially 

 when an open vowel sound is sung on a note of definite pitch, 

 the record is much more easily understood. Then we have 

 the waves following each other with great regularity, and 

 the pitch can easily be made out. Still, as has been well 

 pointed out by Dr. K. J. Lloyd, of Liverpool, a gentleman 

 who has devoted much lime and learning. to this subject, it 

 is impossible by a visual inspection of the vowel curve to 

 recognise its elements. Thus two curves, very similar, 

 possibly identical to the eye, may give different sounds to 

 the ear — that is to say, the ear, or ear and brain together, 

 have analytical powers of the finest delicacy. No doubt, by 

 the application of the Fourierian analysis, we may split up 

 the periodic wave into a fundamental of the same period, and 

 a .series of waves of varying strength vibrating 2, 3, 4, 5, &c. , 

 times faster than the fundamental, and the relative amplitude of 

 each of these may be determined. If all these waves of given 

 amplitude and given phase acted simultaneously on a given 

 particle, the particle would describe the vibration as seen in the 

 original curve. Dr. Lloyd, however, is of opinion that even a 

 Fourierian analysis may not exhaust the contents of a vowel, as 

 it does not take account of inharmonic constituents which may 

 possibly exist. Hermann and Pipping have also been investi- 

 gating the analysis of vowel tones, and their investigations have i 

 revealed many difficulties. liermann experimented with the j 

 ordinary phonograph, and obtained photographs of the move- j 

 ments of the vibrating glass plate. Pipping's curves were not | 

 obtained from the phonograph, but from the vibrations of a | 

 minute membrane made to represent the drum-head of the ear. 

 His curves show large. periodic waves with minute waves on 

 their summits, and they suggest that the large waves may be 

 vibrations due to the membrane itself. I therefore think that 



experiment suggested another of a different kind. Suppose I 

 send the current not only through the variable resistance 

 apparatus above the disc of the phonograph, but also through 

 the primary coil of an induction machine. The wires from the 

 secondary coil pass to two platinum plates dipped in weak salt 

 solution. I now set the phonograph going ; and when I put 

 my fingers into the beakers containing salt solution, I feel the 

 intensity of every note. The variation of intensity, the time, 

 the rhythm, and even the expression of music, are all felt. I 

 shall now place on the mandril of the phonograph a cylinder on 

 which has been recorded another piece of music, with a faster 

 tempo. I now feel a series of electrical thrills corresponding 

 to every variation of intensity of sound coming from the phono- 

 graph. That method shows that the nerves of the skin can be 

 stimulated by irritations coming to it at the rate of the notes and 

 chords of rapid music. Some of the notes produced by the 

 phonograph do not last longer than the five-hundredth or six- 

 hundredth part of a second, but they are quite sufficient to 

 stimulate the nerves of the skin, and, as I have pointed out, 

 you can appreciate the variations of intensity. You can feel 

 the long drawn-out notes from the saxhorn or trombone. You 

 feel the crescendo zxidi diminuendo oixh^jlXrcaxc movement, and you 

 can estimate the duration of the note and chord. You feel even 

 something of the expression of the music. It is rather a pity 

 to say than even expression is mechanical. It is undoubtedly 

 mechanical when you deal with the records of the phonograph. 

 A number of interesting questions of a physiological nature are 

 suggested by this experiment. The skin is not a structure that 

 can analyse tone or distinguish pitch ; it cannot tell you the 

 number of vibrations, although there is a curious approach to it. 

 While it is not by any means accurate, you can distinguish tones 

 of low pitch — very low tones— by a feeling of " intermission." 



Fig. 4. — Portion of a record of the time and intensity of nnusic played by a military band. Each curve represents a note or 

 chord. The curves^are read from right to left. The cylinder in which the record was taken was moving slowly, about 



I inch per second. 



argument as to the character of vowels should be based only on 

 records obtained from the phonograph itself, which is furnished 

 with a vibrator that will not record its own periodic vibrations 

 unless the sound be remarkably intense. In ordinary voice 

 production and in ordinary singing, the vibrator of the phono- 

 graph faithfully records only the pressures falling upon it— no 

 more and no less. 



I shall now show you another method of recording, not the 

 individual vibrations of the phonograph, but the variations in ! 

 intensity of the sounds of the phonograph— the intensities of ' 

 individual notes and chords. I was led to use this method by 

 becoming acquainted with an instrument devised by Prof. 

 Heurlhle, of Breslau. He has succeeded in recording the 

 vibrations of the sounds of the heart. I saw that his instrument 

 was very useful, and I adapted it to the particular purpose in | 

 hand. Heurthle's in.strument is an electro-magnet acting on a i 

 metal plate connected with the elastic membrane of a tambour. 

 Another drum is connected with the first by an india-rubber j 

 tube. The metal plate of the first tambour is pulled down by 

 the electro-magnet ; thus the air is rarefied in the tube and in 

 both tambours, and the lever of the second tambour moves. 

 The next instant the lever flies back. We shall now connect 

 Graham's variable resistance apparatus with the phonograph. 

 As sound waves fall on it, a change is produced in the current ; 

 passing through the electro-magnet ; the latter acts on its 

 tambour ; a variable pressure is communicated to the other 

 tambour ; and if the lever of the latter is brought against a i 

 revolving drum, a tracing is obtained. I show you a little bit j 

 of such a tracing (Fig. 4). 



Each note and each chord is recorded, so that you get a 

 mechanical tracing of the variations of intensity. Now this I 



NO. 1444. VOL. 56] 



Experimenting in this way, you may stimulate by interrupting 

 this circuit at the rate of 30 or 40 or 50 breaks per second, and 

 yet the skin will tell you the individual breaks ; but when you 

 get above that number you lose the consciousness of the indi- 

 vidual breaks, and you have a more or less continuous sensation. 

 The phonograph does not necessarily give you 50 or 60 stimuli 

 to produce a sensation of a tone ; you do not require that 

 number. I found that 8 or 10 per second may give you the 

 sensation for a tone of any pitch. In the same way you may be 

 able to notice a slight difference up to perhaps 50 or 60, but 

 above that the sensation seems continuous. It is not the number 

 of stimuli that determine pitch, but the rate at which the stimuli 

 afTect the sense organ, whether it be ear or skin. Then the 

 question arises, What is it in the skin that is irritated ? It is 

 not the corpuscles. They have to do with pressure. There x-, 

 no organ for the sense of temperature. You may say that the 

 feeling is muscular. Possibly it may be so ; but the effect is 

 most marked when the current is so weak as to make it unlikely 

 that it passes so deep as to reach the muscles. 



This experiment suggests the possibility of being able to com- 

 municate to those who are stone deaf the feeling, or, at all 

 events, the rhythm of music. It is not music, of course, but, if 

 you like to call it so, it is music on one plane and without colour. 

 There is no appreciation of pitch or colour or of quality, and 

 there is no effort at analysis, an effort which, I believe, has a 

 great deal to do with the pleasurable sensation we derive from 

 music. In this experiment you have the rhythm which enters 

 largely into musical feeling. Recently, through the kind- 

 ness of Dr. J. Iverr Love, I had the opportunity of experi- 

 menting with four patients from the Deaf and Dumb Institution, 

 one of whom had her hearing till she was eleven years of 



