Training simulator for evaluating the effectiveness of personal noise protection equipment

Abstract

A description of the laboratory simulator created at Murom Institute for the study of personal hearing protection equipmnent against acoustic noise is presented. General issues of assessing the effectiveness of such equipment are considered. It is shown that in the conditions of the educational process it is sufficient to use a laboratory simulator in the form of a human head manikin, equipped with the hearing organs’ simulators and microphones. The simulator includes a manikin head with a built-in microphone and the internal cavity filled with noise-absorbing material. The microphone is installed so that its center line coincides with the center line of the auricle auditory canal and its working surface (membrane location area) completely covers the hole cross-section in the holder, excluding the sound wave penetration into the area behind the microphone.The second microphone is placed in a special holder near the manikin and provides the noise sound pressure level monitoring in the area where the manikin is installed. Processing of the generated signals is carried out using a program for analyzing spaced acoustic noise based on LabView. Several pairs of electret microphone capsules for general use, type wm61, were selected for the simulator. The first measurements, showing the fundamental possibility of using the simulator in the educational process in the “Technosphere Safety” field of study, were carried out. It is shown that in the octave ranges, measurement accuracy can be ensured at a level of +3 ÷ -0.5 dB, which corresponds to the “Type 2” class in the ANSI system adopted in the USA.