A conversational test for comparing voice systems using working two-way communication links

A conversational test using live two-way communications provides a measure of the actual usability of voice systems, especially when voice quality is degraded. A conversational test developed at NRL was compared with two other communicability tests in a series of experiments using a variety of digital voice processors with data rates from 800 to 32,000 bps. All three tests ranked the voice processors very similarly, but they did not discriminate equally well among different processors. Other advantages and disadvantages of conversational test methods are discussed.