FEBRUARY 9, 1912] 
1. Pitch, timbre and harmony. 
2. Intensity and volume. 
3. Time and rhythm. 
B. Reaction to musical effect. 
C. Power of interpretation in singing. 
The object of the sensory measurements 
is to determine to what extent the individ- 
ual'is psycho-physically capable of hear- 
ing music. For pitch appreciation, we may 
measure the discrimination, making sure 
that we reach the physiological as opposed 
to the cognitive limit of the perception of 
difference.® A rapid survey at about 
twelve selected points within the range of 
pitch from 25 vd. to 2,500 vd. will suffice 
to ascertain if there are any gaps or any 
other peculiarities in the auditory sensibil- 
ity to pitch within the range of tones which 
may be heard as musical. If any peculiar- 
ity is found, it may be surveyed in detail. 
To measure the tonal range of the ear, we 
determine the upper and the lower limit of 
sensibility to tone. The upper limit is, 
however, by far the most variable and im- 
portant as a factor in musical hearing. 
The two ears may differ materially in 
range. 
The perception of timbre may be meas- 
ured by the ability to distinguish a pure 
tone from a series of artificially built-up 
clangs.* The ability to analyze clangs 
§The cognitive limit is the limit set by lack of 
knowledge or training; ‘the physiological is the 
limit beyond which one can not improve. 
‘We suffer great confusion at the present time 
in regard to the use of the term, ‘‘quality’’ of 
tones. Psychologically, pitch is the quality of the 
tone, but in physics, oratory, music, and untech- 
nical language, ‘‘quality’’ is used in the sense of 
timbre, tone-color, or character of the clang. Psy- 
chologically, the word, ‘‘timbre,’’ alone should be 
used in this sense. It is timbre which distinguishes 
the tones of different instruments, the tenor from 
the bass when singing the same note, or the vowels 
of our speech. In each of these cases there is only 
a difference in the number of overtones and their 
relative dominance, for the tone is ordinarily a 
clang built up by the combination of a number of 
SCIENCE 
203 
varies with training, and should only be 
used as a measure of acquired efficiency or 
skill, although the capacity for such skill 
is determined mainly by the natural sen- 
sory capacity for perception of difference 
in timbre. 
While the perception of consonance and 
dissonance depends largely upon training, 
there are fixed limitations in the natural 
sensory capacity which limit the possibility 
for appreciating the agreeableness or dis- 
agreeableness of combinations of tones. 
This ability may be measured by deter- 
mining the ability of the singer in arrang- 
ing a series of pairs of tones in the order of 
their consonance. 
For the attribute of intensity, we should 
have at least two sensory measures: 
(1) the threshold of sensibility to tones in 
each ear; and (2) the discrimination for 
variations in the strength of a familiar, 
relatively pure, musical tone. These meas- 
ures will show the natural capacity of the 
individual for the hearing of faint tones, 
the hearing of intensity accent, and the 
hearing of shadings in the strength and 
volume of tones in musical expression. 
The perception of volume is so intimately 
dependent upon the perception of strength 
of tone, that a separate measure is not 
needed. 
While the perception of time is largely 
associational, we depend ultimately upon 
the sensory capacity for the perception of 
short durations and rhythmic effects. 
Rhythm may be expressed through both 
time and intensity. For a single measure 
of the perception of rhythm as a time ele- 
ment, we may eliminate intensity and meas- 
ure the least perceptible deviation in the 
duration of the recurrent sound, uniform 
in all respects except duration. This, taken 
partials or overtones, each having a pitch of its 
own. Timbre may therefore be regarded as a 
pitch complex. 
