Some trends in modern building technology, such as the use of concrete thermal slabs as heat-sinks, requires that the slab be exposed to the occupied space. In these designs, a continuous (wall to wall) ceiling is not permissible because it could interfere with the airflow pattern around the room. But the downside of not having an acoustic ceiling will probably result in higher reverberation times and increased noise levels above those which would be acceptable to the users. Also in many existing spaces, even though a continuous ceiling is present and has to remain in place for various technical reasons, it may provide insufficient sound absorption than is suitable for the activities being carried out in the room. The installation of canopies in a reverberant space, in sufficient numbers and in a layout to satisfy both technical and aesthetic considerations, can significantly reduce the reverberation time and contribute to the reduction in background noise and improvement of aural comfort.