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 bits/s. 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.