Room and Electro-Acoustical Conditions in Video Conferencing Rooms

Video conferencing (VC) has gained popularity due to the huge progress in the field of telecommunications and networking, leading to better audio and video signal quality, besides its major advantages in saving travel time and cost leading to better environment. Current research trends in VC include studies of how to increase the Quality of Experience (QoE), i.e. the quality of transmitted, coded, and received audio and video signals from one end to another. The QoE depends on many factors such as the quality of the sending and receiving equipment (Microphones, cameras, loudspeakers), the audio/video coders, the network conditions, etc. However an often overlooked factor is the room acoustical conditions. Poor room acoustical conditions can easily ruin the perceived audio quality even if high quality equipment is used. Room acoustical conditions can be predicted by accurate computer programs and simulations, which require much detailed input data and complex computations, or by simple predictions models, which are less accurate but require much less input data. Such simple models are very useful since they can directly illustrate and explain the relations of a few main system parameters. These predictions models exist since a long time ago for single rooms but VC involves two rooms, which makes these classical predictions models not valid for studying VC. The scope of the research in this thesis is how to predict room acoustical parameters using such simple but efficient models that can facilitate parametric studies of the total audio transmission in a VC scenario.