CORRELATION BETWEEN HEADPHONE AND TELEPHONE-HANDSET LISTENER OPINION SCORES FOR SINGLE-STIMULUS VOICE CODER PERFORMANCE ASSESSMENTS

It has often been suggested that digital voice coder performance may d epend on the type of listening set used in listener opinion assessment s. In this letter, the quantitative impact of using headphones and tel ephone handsets is presented for single-stimulus MOS assessments. From this analysis, it is derived that there are significant numerical dif ferences between tests employing these types of listening instruments and that cardinal differences in performance may be consistent and thu s predictable. This study is extended to an ordinal analysis from whic h it is derived that although ranked performance does vary, depending on which of two listening instruments is employed, the two rankings ar e highly correlated.