Cisco Cisco IP Phone 8841 Weißbuch
*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.
Test Procedure
The test was divided into two separate parts, evaluating receive-end and uplink perfor-
mance separately.
mance separately.
The recordings captured the performance of the devices in a range of condi-
tions, including narrowband (NB, 300–3400 Hz) and wideband (WB, 50–7000 Hz) settings for
three languages.
three languages.
All listeners were presented with written instructions, and completed a small familiariza-
tion module prior to starting each of the separate parts. The familiarization module intro-
duced the listener to the variety of test material as well as test methodology and scales.
tion module prior to starting each of the separate parts. The familiarization module intro-
duced the listener to the variety of test material as well as test methodology and scales.
The test was performed on individual listening stations or booths, where the listeners were
seated and given written and verbal instructions. They then proceeded to listen to record-
ings of the products and give ratings according to the methods suggested in the ITU-T
P.800 ACR and ITU-T P.835. To avoid any order-of-presentation effect, each listener was
presented with a unique test randomization in a double-blind paradigm. None of the listen-
ers was informed about which products were under test.
seated and given written and verbal instructions. They then proceeded to listen to record-
ings of the products and give ratings according to the methods suggested in the ITU-T
P.800 ACR and ITU-T P.835. To avoid any order-of-presentation effect, each listener was
presented with a unique test randomization in a double-blind paradigm. None of the listen-
ers was informed about which products were under test.
A total of 96 listeners participated in the ITU-T P.800 ACR test, and 85 listeners in the
ITU-T P.835 test. The tests were performed in three countries using native speaking listen-
ers.
ITU-T P.835 test. The tests were performed in three countries using native speaking listen-
ers.
Results: Receive End
Receive-end performance captures how the device reproduces the speech signal from the
incoming call. It is the audio quality that is experienced when listening to the device in real
use cases.
incoming call. It is the audio quality that is experienced when listening to the device in real
use cases.
Differences in performance were found for both narrowband and wideband settings. The
magnitude of difference between the performances is in the range of 0.2 Listening Quality
Mean Opinion Scores (LQ-MOS). All systems tested significantly different (P<0.001).
Refer to Error! Reference source not found. for details.
magnitude of difference between the performances is in the range of 0.2 Listening Quality
Mean Opinion Scores (LQ-MOS). All systems tested significantly different (P<0.001).
Refer to Error! Reference source not found. for details.