Researches in experimental phonetics. 63 
arrangement involving an anticipatory adjustment of the vocal organs 
whereby the vowel is prepared for before the h is produced. 
The hu glide. 
The aspirate h is followed by two vibrations with periods of 2.3° and 
2.i<r respectively (Fig. 71, line 2). They are resonance vibrations pro¬ 
duced by the passage of the air through the mouth cavity. They might 
with propriety be considered as belonging to the h, from which they 
differ only in period. Yet the change from the h period of 2.5° denotes 
the rise of an impulse toward another sound and, if the concept of a 
glide is to be admitted at all, they are to be treated as a glide. The 
intention shown in the glide is to change the mouth tone from 2.5^ 
for the h to 1.9er for the u. The second of these glide vibrations ends 
suddenly with the puff of air from the first vibration of the cords in mak¬ 
ing the u. 
The vowel u. 
The word is so short that the ear is not able to attribute any particular 
quality to the vowel. 
The curve for the u (Fig. 71, lines 2 and 3) closely resembles that for 
ai in its general character. The first part shows a rising cord tone and 
a nearly constant but afterwards falling resonance tone. In the latter 
portion the cord tone is approximately constant while the resonance tone 
falls. The change in the character of the action of the cords appears 
clearly also as in ai (p. 37). It is, in fact, very evident that this sound 
is really a diphthong with possibly less difference between the two ele¬ 
ments than in the case of ai. This diphthongal character of the English 
it is well known to phoneticians ; the sound is generally indicated by mu. 
A separation of the sound into its two parts will not be attempted here. 
The curve at the beginning of the u shows a vibration of 6.3° from 
the vocal cords acting on a cavity whose period r-9ff is not a sub-multiple 
of the cord period. As the cord period is gradually shortened, the reso¬ 
nance period (remaining the same) steadily modifies the form of the re¬ 
sultant vibration, and the curve is seen to change its form gradually. 
The relation between cord tone and resonance tone is closely analogous 
to that in the a of ai (p. 19). 
The successive vibrations of the « occupy the periods of 6.3, 6.1, 6.1, 
5.6, 5.4, 5.4, 4-9. 4-9» 4-9» 4-9. 4-9. 4-6, 4-6, 4-6, 4-2, 4-2, 4-2, 4-2, 
4.2, 4.2, 4.2, 4.6, 4-6, 4.6, 4.6, 4.6, 4.6, 4.6, 4.6, 4.6, 4.6, 4.6, 4.6, 
4.6, 4.6ff. The total time occupied by the u is 167^. 
The u thus shows a sudden tightening of the cords to a tension neces¬ 
sary for a tone with a period of 6.3* and thereafter a gradual increase of