Developing a signal device supporting prevention of exposure of earmuff users to noise

The aim of the task was to develop a signal device supporting prevention of exposure of earmuff users to noise. The devices were developed for new models of earmuffs to alert their users about excessive exposure to noise resulting from an incorrect use or selection of earmuffs. It was accepted that the developed device would signal exceeding exposure of - 85 dB of A-level sound - 115 dB of A-level sound, - 135 dB of peak C-weighted sound pressure level. Block diagrams of signal devices were developed. Then electronic circuits were designed and produced, they function as the individual blocks of the model. The construction and the operation of those blocks were verified with simulation and laboratory tests. On that basis models of two versions of signal devices were designed and produced. They were calibrated and verified in laboratory conditions. Different models of earmuffs with built-in signal device supporting prevention of exposure of earmuff users to noise were designed and produced. The signal devices used in those models were based on miniaturized models. A new kind of signal devices was also developed - miniature portable signal devices that can be fitted inside any earmuffs to measure noise and to signal excessive exposure. The models of earmuffs with built-in signal device supporting prevention of exposure of earmuff users to noise developed within the task, and the portable signal devices were tested in real and laboratory conditions. Those tests concerned the operation of the signalling devices and their suitability for various types of noise. A patent was submitted for the technical solution related to the fitting of the signal device supporting prevention of exposure of earmuff users to noise in the earmuff.