Voice & Audio Quality Testing
What is POLQA?
Perceptual Objective Listening Quality Analysis (POLQA) is the latest (2011) objective measurement for speech quality standardized (ITU-T P.863). POLQA is an enhancement to the PESQ algorithm (ITU-TP.862) introduced in 2003 which allowed perceptual speech quality measurements to become a mainstream method to evaluate end-to-end speech clarity. Perceptual speech quality measurements are needed when speech is compressed such as in a voice codec (e.g., G.729, G.711, G.722, AMR-WB, EVS, etc.) and then transported over wireless or IP-based networks.
The POLQA algorithm was introduced to deal with some of the weaknesses inherent in PESQ, as well as to address wideband telephony or HD voice (i.e., voice communication above 3.4kHz).
The principle is similar to PESQ — comparing the clean reference file with the degraded file from the network. But the test methodology is different. POLQA has two models, one for narrowband and one for super-wideband. The POLQAv3 (download POLQAv3 multi DSLA Datasheet) goes to full-wideband, the full range of the human ear, and can be used for any network from 300–24,000Hz analog bandwidth. The narrowband POLQA algorithm is for legacy telephony on networks up to 3.4kHz and provides compatibility with PESQ NB and narrowband subjective test data.
MultiDSLA makes it easy to use POLQA. Malden’s long experience in the application of speech quality metrics, inherited by Opale, ensures that you will be getting useful results as soon as the POLQAv3 option is enabled on your MultiDSLA system.
Why Is POLQA Useful?
The main driver for the new POLQA standard was wideband telephony, sometimes called HD-voice as defined by the G.722 and G.722.1 (wideband AMR). In addition, POLQA analyzes speech to the limit of the human ear (24kHz analog bandwidth). The POLQA algorithm supports measurements from 300–3.4kHz including traditional PSTN telephony (when set to the narrow band scale), wideband (WB up to 7kHz), super-wideband (SWB, 50–14kHz), and fullband (FB, 50–24kHz).
