Early Instruments in Auditory Research: The Lehmann Acoumeter
* Presenting author
The Lehmann Acoumeter, an instrument developed in the late 19th century, is a tabletop device designed to generate impulse sounds of varying level. Compared to other purely mechanical instruments that evaluate hearing, e.g. tuning forks, sound pendulums, or a pocket watch, the design of the acoumeter is more sophisticated. An impulse is generated by dropping a steel ball on a miniature glass plate. A pair of forceps, that are finely adjustable in height, are used to release the shot. My presentation involves highlighting the design of the acoumeter and exploring which niche it filled among the number of other acoustic instruments available at the time. My main hypothesis is that because of the detailed instructions, the accuracy of the height adjustment, and the wide availability of the compact system, the acoumeter was an important step towards standardizing the measurement procedure of auditory tests. Because of the time commitment to determine one’s hearing threshold using the acoumeter, it is unlikely that the instrument was used in clinical settings. Instead, it may have been used in laboratories that aimed to assess the hearing of study participants in preparation for, or for the use of psychophysical tests.