|ITU-T recommendation for voice quality testing|
- MUSHRA (Multiple stimulated with hidden reference and anchor) , In MUSHRA we use "lossy audio compression algorithm". MUSHRA ratified by ITU-R BS 1534- 2 and ITU- R BS 1534-3. It's a subjective evaluation system.
- PSQM (Perceptual speech quality measurement) is such a measurement system which allows automated and simulation based methodologies for rating both voice clarity and transmitted voice quality. This system ratified by ITU-T P 861. In PSQM, we use a psychoacoustical mathematical modeling algorithm to analyze the pre and post transmitted voice signals. ITU-T already replaced PSQM(ITU-T P861) by PESQ (ITU-T P862).
The thematic presentation of PESQ SQI MOS is given bellow:
- PESQ (Perceptual evaluation of speech quality) was developed as a model of subjective tests as per industry standard which will be widely used in Telecommunication system. It was standardized as ITU-T recommendation P.862 (02/01). Latter PESQ scores mapped into MOS score which was standardized as ITU-T P862.1. The scoring values of PESQ SQI MOS(speech quality index mean opinion score) ranges from 1 to 5 inwhich 1 means worse and 5 means best. The final score of PESQ SQI MOS is the arithmetic mean of all the tested scored.
|Geographical distribution of PESQ SQI MOS Score from DT log|
- POLQA (Perceptual Objective Listening Quality Assessment) is the most recent ratified voice quality assessment system and best suited for wide band audio signal measurement. POLQA covers a model to predict a speech quality or alternatively we can treat it as digital speech signal analysis and rating procedure. POLQA was developed as per ITU- T 863 recommendation. It's the most widely implemented voice assessment system and excellent successor of PESQ (P8621). As like PESQ values POLQA scores ranges from 1 to 4.5. POLQA score evolution almost like PESQ. 1 means worse and the value equivalent to 4 or above 4 is excellent.
|POLQA Reference vs Degraded audio signal|