This is possible if the wrong Hardware Sample Rate is selected. The Hardware Sample Rate specifies whether Umetrix Voice scores the degraded file against a wideband or narrowband reference file. To confirm that the correct Hardware Sample Rate is selected, navigate to the Settings → Voice Quality tab and check which Hardware Sample Rate is selected.
The Narrowband (8 kHz) option records downlink .WAV files at 8 kHz linear PCM format. Narrowband sampling is the default selection and it used for standard handset testing.
The Wideband (16 kHz) option records downlink .WAV files at 16 kHz linear PCM format. Wideband sampling can be used when sourcing and receiving both links from two channels within Umetrix Voice in order to simulate an ideal downlink and uplink environment. Wideband sampling is not available when testing with the Audio Server due to the bandwidth limitation within the PSTN.