1896 - 97 .] 
Chairman's Opening Address. 
201 
The Curves. 
Since the apparatus was brought to its present condition, I have 
been able to record the vibrations of the tones of several instru- 
ments and also the tones of the human voice both in singing and 
in speech, but there has not yet been leisure for a careful scrutiny 
of the records, and I shall therefore, on the present occasion, offer a 
few general remarks. 
First, with reference to speech, I wish to point out that when 
the record of a ivord is examined it is found to consist of a long 
series of waves, the number of which depends (1) on the pitch of 
the vowel constituents in the word, and (2) on the duration of the 
whole word or of its syllables individually. There is not for each 
word a definite wave form, but a vast series of waves, and, even 
although the greatest care be taken, it is impossible to obtain two 
records for the same word precisely the same in character. A 
word is built up of a succession of sounds, all usually of a musical 
character. Each of these sounds, if taken individually, is repre- 
sented on the phonograph record by a greater or less number of 
waves or vibrations, according to the pitch of the sound and its 
duration. The pitch, of course, will depend on the number of 
vibrations per second, or per hundredth of a second, according to 
the standard we take, but the number of the waves counted depends 
on the duration of the sound. As it is almost impossible to utter 
the same sound twice over in exactly the same fraction of a second, 
or in the same interval of time, the number of waves counted varies 
much in different records. The rate per unit of time determines 
the pitch, the number the duration of the sound. In a word, 
these successive sounds blend into each other, and, in many records, 
the passage from one pitch to another can be distinctly seen. The 
speech sounds of a man to the ear not consciously engaged in 
analysis, appear to vary in pitch from 100 to 150 vibrations per 
second, and the song sounds of a man from 80 to 400 vibrations 
per second. The sounds that build up a word are chiefly those of 
the vowels. These give a series of waves, representing a variation 
in pitch according to the character of the vowel sound. As in the 
record of a spoken word the pitch is constantly moving up and 
down, the waves are seen in the record to change in length. 
