Influence of Sound-Absorbing Material Placement on Room Acoustical Parameters

The reverberation of a room is often controlled by installing sound absorption panels to the ceiling and on the walls. The reduced reverberation is particularly important in classrooms to maximize the speech intelligibility and in open-plan offices to make spaces more pleasant. In this study, the impact of the placement of the absorption material in a room was measured in a reverberation room and in a mockup classroom. The results show that absorption material is less efficient if it is mounted to the corners or on the edges between the walls and ceiling, if the sound field is more or less diffuse. If the room modes dominate the sound field, the most efficient location for the sound-absorbing material was found at one of the surfaces causing the modes. The results help acoustical consultants to place the absorption material in optimal locations and, generally, minimize the amount of material and save costs.