Cisco Cisco IP Phone 8841 Libro bianco
*This document is a summary report. For full description of listening test, please refer to the document
“‘SenseLab 005-13”.
“‘SenseLab 005-13”.
The report must not be reproduced, except in full, without the written approval of DELTA.
Results: Uplink
Uplink performance describes the quality of the signal sent from the device. It includes the
speech signal and some level of background noise. Uplink performance is typically not
experienced directly by the device user, but instead influences how the receivers of the call
experience the audio quality.
speech signal and some level of background noise. Uplink performance is typically not
experienced directly by the device user, but instead influences how the receivers of the call
experience the audio quality.
Three test questions are used to assess the following parameters:
• Background noise: The CP-8831 performed significantly better than the IP 7000 in
suppressing the background noise (simulated ventilation noise). The magnitude of
difference is between 0.8 LQ-MOS for narrowband and 1.0 LQ-MOS for wide-
band settings.
difference is between 0.8 LQ-MOS for narrowband and 1.0 LQ-MOS for wide-
band settings.
• Distortion of speech: The two systems performed statistically similar in wideband
settings. For narrowband the CP-8831 performed significantly better in the range
of ~ 0.1 LQ-MOS.
of ~ 0.1 LQ-MOS.
• Overall quality: The CP-8831 performed significantly better than the IP 7000 in
the overall quality test question. The magnitude of difference is in the range of
~0.3 LQ-MOS. Refer to Error! Reference source not found. for details.
~0.3 LQ-MOS. Refer to Error! Reference source not found. for details.
DELTA SenseLab
DELTA is a Danish technology company that is a part of GTS – Advanced Technology
Group, approved by the Danish Ministry of Science, Innovation, and Higher Education.
DELTA SenseLab is an independent test laboratory specializing in performing listening
and perceptual tests of audio codecs, audio hardware, hearing aids, and telecommunication
devices.
Group, approved by the Danish Ministry of Science, Innovation, and Higher Education.
DELTA SenseLab is an independent test laboratory specializing in performing listening
and perceptual tests of audio codecs, audio hardware, hearing aids, and telecommunication
devices.
DELTA, 02 July 2013
Jesper Ramsgaard
Specialist, SenseLab
Søren Vase Legarth
Head of Dept. SenseLab