Improvement of interior acoustics and speech quality in small office room using natural material

This paper is based on an experimental work for improving the acoustics of a small office room. The sound absorbing properties of a naturally occurring plant fiber material, jute is measured and used to reduce the reverberation time of the room. Carpets of two different thickness of jute material are used to demonstrate the reduction in the measured reverberation time in the room. Results from experimental measurements on the background noise level and the noise reduction in the room due to air-borne attenuation across the walls due to a pink noise excitation are presented. The speech intelligibility of the room is also objectively quantified by measuring the speech transmission index in the room with and without the jute carpets. It is also shown how the reverberation time influences the speech transmission index. Jute can thus be used as a material for building acoustics.