Acoustic Measurements and Psychoacoustic Analyses of Ventilation Diffusers

People in industrialised countries spend most of their days indoors and are often exposed to ventilation sounds. Since ventilation systems are not only used in industry but also increasingly in residential buildings, it is important to study its sound radiation and the consequences for our well-being. This research project aims to identify if geometric features of air diffusers affect the rated annoyance of ventilation systems. It is known that the A-weighted sound serves as a criterion to a limited extent. Therefore, psychoacoustic analyses and evaluations need to be included to find out if there are correlations between psychoacoustic features and flow phenomena caused by the geometric features of the air diffusers. Several air diffusers were acoustically measured in a hemi-anechoic room using a developed mobile ventilation unit that supplied the necessary air volume flow. The ventilation unit could be operated in both supply and extract air configuration of the diffusers. The measured data not only includes the acoustic directivity of the air diffusers but also recordings that are needed to conduct listening tests. To increase the ecological validity and to study the role of the environment, future listening experiments will be also extended to audio-visual experiments in virtual reality.