First ISCA ITRW on Auditory Quality of Systems

April 23-25, 2003
Akademie Mont-Cenis, Germany

Speech Quality of Heterogeneous Networks Involving VoIP: Are Time Varying Impairments Additive to Classical Stationary Ones?

Alexander Raake

Institute of Communication Acoustics (IKA), Ruhr-University Bochum, Germany

This paper describes a series of four conversation tests, which were carried out in order to assess speech quality under degradations occurring in combined PSTN/ISDN/VoIP networks. Based on the test results, the validity of predictions by the model currently recommended by the ITU-T for network planning (the E-model, [1]) is discussed.


  1. ITU-T Rec. G.107, The E-Model, a Computational Model for Use in Transmission Planning, International Telecommunication Union, CH-Geneva, 2002.

Full Paper

Bibliographic reference.  Raake, Alexander (2003): "Speech quality of heterogeneous networks involving VoIP: Are time varying impairments additive to classical stationary ones?", In AQS-2003, 63-70.