The following is the first report showing a systematic survey of the hearing of all the school children of a large city, from 9 to 16 years of age.
The introduction of the phonograph audiometer1 (Western Electric No. 4-A) made possible the testing of the hearing of a large number of persons at one time. This instrument is now used in many cities for the examination of school children.
The phonograph audiometer (fig. 1) is an instrument consisting of a phonograph and records through which speech vibrations, consisting of numbers, are conducted to telephone receivers attached to the hearers' ears. Forty persons can be tested at one time. Figure 2 shows an arrangement of such a group. Blank forms (fig. 3) are distributed to the children on which they write the numbers as they hear them. The loudness of the consecutive numbers is decreased in uniform steps, and by comparing
RODIN FH. SURVEY OF THE HEARING OF THE SCHOOL CHILDREN OF SAN FRANCISCO. Arch Otolaryngol. 1930;11(4):463–474. doi:10.1001/archotol.1930.03560040079009