Summary

Supplement 27 to the ITU-T P-series of Recommendations provides a method for the application of ITU-T P.863 to speech signals processed by a blind bandwidth extension (BBE), which is complementary to the existing procedures given in Recommendation ITU-T P.863.1. When bandwidth extension techniques are used, not only does the reference bandwidth need to be set but ITU-T P.863 also has a limited ability to discriminate small bit rate and bandwidth improvements. These quality differences are clearly distinguishable in subjective tests. For ITU-T P.863 tests, a complementing bandwidth requirement check is needed and detailed.