776 
tion conducted by Dr. Warner Fite and 
the present writer upon the capacities of 
auditory localization in a man totally deaf 
in one ear. The readers of SclENCE may 
be interested in a brief statement of the 
essential facts observed. 
The subject of the experiments is a man 
of thirty, who lost his hearing in one ear 
during early childhood, as the result of 
scarlet fever. The present symptoms, as 
reported by expert clinical test, indicate 
total nerve- deafness and consequently lesion 
of the labyrinth. The drum membrane 
was originally destroyed by ulceration of 
the middle ear and a scar has now replaced 
it. The precise condition of the bones of 
the middle ear cannot be determined. The 
malleus appears to be intact. The uninjured 
ear is decidedly more acute than the aver- 
age, but in no such degree as would war- 
rant the term hyperesthetic. 
Without entering into details, the appa- 
ratus employed in the experiments may be 
described as consisting of a mechanical 
device, whereby noises and tones may be 
given in various directions and ata constant 
distance from the subject’s ear. The ar- 
rangement permits the exact registration, 
in connection with the surface of an imagi- 
nary sphere, of each location from which a 
sound is given. The instrument permits 
all the adjustments to be made noiselessly, 
so that the subject, who keeps his eyes 
closed during the experimentation, receives 
no suggestion whatever of the direction 
from which the sound proceeds. The stimuli 
used consisted of tuning fork tones, the 
tones of a Galton whistle and the snapping 
sound made by sending an electric current 
through a telephone. The tones of the 
forks are practically pure. The notes of 
the whistle are more complex and the noise 
of the telephone is highly complex, contain- 
ing a large number of partial tones. 
Tt will facilitate a succinet statement of 
the results to imagine the subject seated in 
SCIENCE. 
[N.S. Vou. XIII. No. 333. 
the center of a large clock dial placed hori- 
zontally. The figure twelve is directly in 
front, the figure six behind, three is oppo- 
site the right ear and nine opposite the left 
ear, which is deaf. The sounds of which 
we shall speak first are given at the height 
of the ear. 
Pure tones are almost, if not wholly, un- 
localized by this subject. Often he can 
assign no position whatever to such tones, 
and, when he does hazard a location, the 
percentage and character of error show that 
the process is extremely inaccurate. On 
the other hand, complex sounds are local- 
ized with an accuracy which follows closely 
the number and audible nature of the par- 
tial tones they contain. The one exception 
to this is the region lying between eight and 
ten on the face of our illustrative dial. 
This is the region immediately opposite the 
deaf ear. To offset this defect the discrim- 
ination between positions immediately in ~ 
front and those directly behind is superior 
to that of normal persons, for whom this 
distinction is notoriously uncertain. For 
the remaining regions, from ten toward the 
right around to eight, the localizations are 
only slightly inferior to those of normal in- 
dividuals. Occasional confusions of the 
right and left hemispheres occur, which are 
almost unknown to binaural hearing. But 
in general, both as regards the character of 
the error and as regards the amount, the 
localizations are surprisingly like those of 
the binaural type. 
In normal persons the localization of 
sounds is commonly supposed to depend 
upon the differences in the stimulations 
reaching the two ears. These differences 
are describable as partly differences in in- 
tensity and partly differences in quality. 
Thus, a sound opposite the right ear, for 
example, stimulates that ear more intensely 
than it does the left ear, and, if it be a com- 
plex sound, more of its component over- 
tones will be noticeable to the right ear 
