ProSA – Protection and Situational Awareness

Level-dependent hearing protectors alter important sound properties, thus leading to a loss of information. Acoustic warning signals can be missed, or colleagues not heard. Level-dependent means that the amount of sound allowed through is controlled electronically. If the ambient environment is quiet, the sound is let through or even amplified. If it is noisy, the sound is drastically attenuated. The advantage of this technology is that you can leave your hearing protectors on when it is quiet, and you want to talk to a colleague. If it suddenly becomes noisy, your hearing is still protected. Little is known so far about the extent to which this technology influences users’ auditory perception of their environment or about the best methods for measuring it. The main aim of the “ProSA” (Protection and Situational Awareness) project is therefore to lay the groundwork for evaluating level-dependent hearing protection systems in the future in terms of the most important effects on auditory characteristics, using practical and time-saving measuring techniques.

In general, established measuring techniques for evaluating sound and environmental perception are too complex or too sophisticated in terms of measuring technology for a measurement of hearing protectors that would be relevant for certification purposes in the long term. Within the project, the researchers will collect experimental data via hearing tests, which will be used to develop and validate models, which, in turn, can allow conclusions to be drawn about the effects of hearing protectors on auditory perception on the basis of technical measurements (e.g., with an artificial head).

The project is scheduled to run for three years, from January 2024 to December 2026. Sina Buchholz, a research assistant at Fraunhofer IDMT in Oldenburg, is responsible for most of the scientific work, which she is conducting in the context of her doctoral dissertation. This project follows two previous theses written in cooperation with Fraunhofer IDMT, in which various aspects of different hearing protectors were measured. The work revealed that there could be safety-critical problems in users’ situational awareness in some cases. From this arose a need for further research, namely, to determine whether these are systematic problems that can potentially be predicted with the help of models. Besides that, another project, “SmartProtect”, explored innovative technologies for intelligent hearing protection solutions for the future. Measuring techniques were also implemented and tested for this purpose, which will be incorporated in the “ProSA” project.