[Mobile soundproof booth for audiometric industrial testing]

The authors modified a caravan for the purpose of audiometric testing in the neighbourhood of industrial workplaces. The sound insulation of the caravan increased due to the use of double glasses in the windows, special tightening of the doors and covering the walls with sound absorbing material. The gained insluation enables the testing of the threshold of hearing in a surrounding where the ambient noise does not exceed foolowing octave-band noise levels: 49 dB--125 Hz, 59 dB--250 Hz, 57 dB--500 Hz, 74 dB--1000 Hz, 81 dB--2000 Hz, 91 dB--4000 Hz, and 100 dB--8000 Hz.