scope:

In this Recommendation¹, a subjective test methodology has been developed as a general subjective test for evaluating speech quality in "listening only" test scenarios. This Recommendation is appropriate for use in a wide variety of bandwidths, including clean and error channel conditions, and clean and noisy background conditions. However, as opposed to most "listening only" tests (for example, [ITU-T P.800] test variants and [ITU-T P.835]), such different categories of test conditions can be mixed within the same ITU-T P.806 test and still provide meaningful results. Results derived from ITU-T P.806 testing are less susceptible to the effects of test context (i.e., the overall composition of the conditions within a test) than any other Recommendation for "listening only" subjective speech quality testing.

¹ This Recommendation includes an electronic attachment containing audio samples for the conditions described in Appendix I.