During the 70's
Instruments for Hearing Research
The 1703 Recording Audiometer was designed to be used under conditions in which large numbers of subjects must be tested in minimum time -- as in industrial hearing conservation programs.
The 1704 Audiometer was a two-channel, fixed frequency, pure-tone/speech manual audiometer with range, accuracy and flexibility suitable for diagnostic applications.
The 1702 provided identical features but added the capability of automatic Bekesy type fixed frequency presentation and recording to the manual capabilities of the 1704.
The 1701, the most sophisticated unit of the G-S audiometer line, was a full-fledged sweep-frequency/speech audiometer available in both manual and automatic versions, and suitable for the most exacting clinical and research applications. The G-S 1720 Otoadmittance Meter was a precise and convenient tool for deriving objective information about the middle ear. The 1720 measured acoustic admittance as a function either of variable air pressure in the ear canal or of acoustic reflex.
The G-S 3951 Evoked Response System was a versatile package consisting of a signal averager, recorder, neurological amplifier, and sufficient digital control equipment to implement a variety of procedures involving cortical potentials.
