Room Acoustic Conditions for Audio and Video Conferencing

A video conferencing situation combines the acoustical properties of two rooms. As the talker is located in a one room, the sound reaching the listener in an other room will be colored by the acoustical characteristics of both of them. This thesis aims to survey the current conditions in a selection of video conferencing rooms, by investigating several room acoustic parameters involving background noise, re- verberation time, speech clarity and speech intelligibility. Convolution of recorded impulse responses enables the rooms to be combined, and the combined results to be evaluated. The evaluation of the results allow limit values for acceptable quality for video conferencing to be suggested. Limits for the highest acceptable values for the early decay time and the lowest acceptable values for speech clarity are sug- gested both for the single-room situation, and for the combination of rooms. The suggested values are based on specifications from building standards and relations between measured room acoustic descriptors