Method, device and system for altering the reverberation time of a room

摘要: The invention relates to sound-absorbing devices, assemblies and systems corresponding methods for altering the reverberation time of a room, specifically although not necessarily exclusively at low frequencies. A device according comprises basically body containing one or more cavities (4), where least portion outer surface is in contact with said sound field S inflatable/extendable collapsible/compressible during supply gas removal from cavity respectively, whereby absorption coefficient (a) and/or resonance frequency can be varied, thus determining region which maximum will take place.