In 1932 I suggested a graphic method of tuning fork audiometry.1 The method was tedious and not based on a standardized scale of normal hearing. It was abandoned.
In 1934 I devised the acoustimeter. This consisted of a series of calibrated tuning forks mounted on a revolving turret. The forks were struck by a swinging hammer allowed to drop from a constant level. A stop watch connected with the hammer indicated the duration of audibility (from the time the fork was struck to the loss of audibility). The number of seconds of audibility was marked in a corresponding place on the chart. This at once showed the loss of hearing in decibels.
In connection with this instrument the principles of modern audiometric arithmetic were for the first time applied to precision tests of acuity of hearing with tuning forks as the source of sound.
However, the instrument was cumbersome, expensive