Programmable electroacoustic test system

Abstract

A portable electroacoustic system has been assembled around a BASIC-programmable calculator for use in a variety of laboratory acoustical tests. The system contains a precision frequency synthesizer, a sample/hold, ac/dc volt meter, a coordinate-digitizing tablet, an x-y plotter, a frequency counter, and a programmable relay box for test control. The entire system is mounted on a mobile console. Principal considerations affecting the system design were that it be (1) as easy as possible to program and operate, (2) composed of off-of-the-shelf equipment, and (3) as flexible as possible in laboratory acoustical applications. The most successful application of the system has been the semiautomated processing of audiometric test results. Other automatic testing applications have included (1) anechoic chamber testing of sound-level meters, (2) dynamic response testing of occupational noise dosimeters, and (3) pure-tone audiometric testing. Additionally, the system has been connected to a third-octave-band analyzer for measurement of noise reduction characteristics of a sound-proof room. The ability of the system to perform statistical data processing as part of the test has been of great value.