We generally recognize that when one system operates twice as fast as another, it is the superior solution. But it's not so easy with voice. Everyone's Got an Opinion Traditionally, voice assessments are made by gathering opinions from a group of participants operating in a sterile test environment. This is the approach we've taken most often in Network Computing's testing of voice products and services. It's an intense and time-consuming process that requires a large sample of people because different people can perceive the same system as having radically different quality.
Perceptions also vary based on age and language.
It describes test-lab conditions, the content of audio samples and scoring, and how data should be analyzed. Because P. 800 tests can provide ambiguous results, substantial dissension has arisen among scientists and engineers regarding its use. Even its authors warn against comparing MOS scores taken under different conditions. Second, the language itself used in P.800 is open to subjective interpretation. Change the vocabulary and the results change.