The hygienic requirements in health facilities, in particular in hospitals, lead in most cases to hard and high reflective surface materials and subsequently to long reverberation times. The noise level is high and the resulting speech intelligibility is low - both indicating poor room acoustics with stress-increasing impacts. In contrast, good room acoustics will help staff members to work more concentrated and with less mistakes and patients will profit from a better prevention, regeneration and healing. Sound absorbers generally reduce reverb and create a comfortable acoustic environment. Additionally, sound absorbers for health facilities and hospitals need to reach the hygienic requirements on cleaning and disinfecting surfaces. This means in general, that surfaces need to be non-porous and smooth to implement the hygienic requirements, however, porous materials like foams are regularly used for sound absorbers. The purpose of the project was to develop a sound absorber that can be disinfected easily and with material that is chemically resistive to the usual disinfecting products. Constructive and acoustical solutions were developed and evaluated to meet the requirements of a high effective sound absorber with an aesthetic non-technical appearance to be used in common patient rooms and for specific applications in health facilities.@en

In offices and most other working environments a high speech privacy and a low noise level is desired to allow for concentrated work and calm work conditions. Hence a low Speech Transmission Index (STI) is required, as even irrelevant speech information at lower volumes can be extremly disturbing and performance reducing. At the same time working environments demand for other - often conflicting - requirements such as transparency to ensure visual connections and daylight transmission, functional flexibility for diverse activities in the same space and for hygienic, environmental or security aspects. These requirements have to be balanced by a sensible and intelligent design and layout of absorbers and partition elements and partition. Three research projects investigated an optimised design of low and mid frequency absorbers for working environments to improve the acoustic and design quality of different products. Acoustically optimised indoor spaces may become more important in the future due to an increase of hearing impairments in the aging population as well as in the younger generations. This is seen not only as a technical but as a design challenge to balance optimised sound pressure levels, reverberation times and Speech Transmission Indices.@en