Virtual ceiling systems for meeting rooms in open plan offices

Large open plan offices have advantages of low cost construction and flexibility, but they sometimes lack speech privacy and generate sound disturbance when people are talking. Installing small closed meeting rooms inside open plan offices is a good solution to the problem, but the ceiling increases the cost of the meeting rooms due to the requirements of fire safety regulations and extra ventilation and lighting systems. Having the ceiling open or removing the ceiling of the meeting rooms is an option; however, the challenge is the low speech privacy caused by sound wave propagation through the opening. This paper shows an example to analyse relative contributions of different acoustic paths to speech privacy from the opening of an open ceiling meeting room in an open plan office based on the impulse response separation method, and demonstrates a virtual ceiling system in a large open plan office. Preliminary experimental results show the feasibility of the virtual ceiling system and also its limitations. Finally, future research directions for the virtual ceiling systems are discussed.