Auralization of complex noise situations in the Internet
The individual assessment of the aural environment is based on the point balance of acoustic stimuli being present almost everywhere and permanently. The respective intensity, dose and characteristics of the sound events as well as a series of accompanying factors generate a cumulative effect exceeding the tolerable extent more and more frequently. But what is the tolerable extent? Are the individual sound sources too loud, do they occur "in the wrong place and at the wrong time" or in too many places? Experts answer these questions by figures from regulations and guidelines, which most people concerned do not understand. Discussions and planning processes are affected by this. The link is missing, which can create an audible connection of subjective perception of sound, technical reduction measures and defined noise limit values. This scenario clearly requires auralisation nowadays available online and in a new dimension. Behind the auralisation tool developed by the Fraunhofer IBP is an independent browser, which synthesizes the different sounds of a cumulative noise situation. The basis is numerous sound files, the modifications of which are simulated by freely selectable transmission paths, and which can be assessed as an audio sample.
The "mixer console" for example is a novelty for road traffic. In order to be able to react on almost every traffic situation adequate traffic noise is generated from noise files of individual pass-by recordings and determined traffic data. This noise and other sounds as well as noise barriers and sound-insulating windows, open-porous asphalt and other noise control measures are audibly combined and auralized. The program, which is freely accessible in the Internet, gives the chance to get an impression of modified ambient noise and available reduction measures without expert knowledge but only by one’s own hearing. The auralisation program certainly contributes to a better understanding of acoustic relations and effects. In this context, several informative modules and the "audio play" with acoustically relevant parameters, for example noise barriers, are helpful means. The modular structure of the program is simultaneously the condition of projected enhancement, for example a "traffic lights module" for the realistic representation of urban traffic scenarios, or the implementation of timetables and flight schedules. The developed auralisation tool will not make our world more silent, but it offers the potential to objectify many difficult discussions on ambient noise.