Comparison of Perceptual Voice Quality of VoIP Provided by G.711 and G.729 Using Conversation-Opinion Tests
Therdpong Daengsi, Saowanit Sukparungsee, Chai Wutiwiwatchai, Apiruck Preechayasomboon · 2012
This paper reports the results from the study about perception of Thai users to the voice quality of VoIP provided by two codecs, G.711 and G.729, referring to packet loss. The conversation-opinion tests have been conducted with 250 participants to obtain the Mean Opinion Score. This study found that the user perception to G.711 and G.729 is not different significantly referring to the packet loss rates of 0%, 2%, 6%, 10% and 20% approximately. However, the trend of the difference is increased according to the increment of packet loss rates of 10% and 20% in the network. Therefore, it can be recommended to use G.729, which requires only 8 kbps for its voice payload, compared to G.711 that requires 64 kbps, particularly with packet loss of 6% or below, to reduces traffic in the IP network.