ATTENUATION OF EARMUFFS USED SIMULTANEOUSLY WITH RESPIRATORY PROTECTIVE DEVICES/TLUMIENIE DZWIEKU NAUSZNIKOW PRZECIWHALASOWYCH STOSOWANYCH JEDNOCZESNIE ZE SPRZETEM OCHRONY UKLADU ODDECHOWEGO

Background: In the work environment, apart from the noise, employees may be exposed to other harmful factors. Therefore, they wear hearing protectors and other personal protective equipment. The aim of the study was to determine whether simultaneous use of earmuffs and respiratory protective devices affects the attenuation of earmuffs. Material and Methods: The study was conducted in laboratory conditions using the subjective REAT (Real Ear Attenuation at Threshold) and objective MIRE (Microphone in Real Ear) methods. The REAT method was used to measure sound attenuation of earmuffs, while MIRE was used to determine changes in attenuation of earmuffs due to the use of other personal protective equipment. Results: The study showed reduction in attenuation of earmuffs due to the use of a full face mask up to 20 dB. Using a full face mask causes that attenuation of earmuffs in the low frequency range is close to zero. Reduction in attenuation due to the use of half masks for complete with particle filters (half masks) is 3-15 dB. Simultaneous use of earmuffs and filtering half masks makes small changes in attenuation not exceeding 3 dB. Conclusions: The study showed that full face masks give the greatest reduction in attenuation of earmuffs. On the other hand, the least reduction is observed in the case of filtering half masks. There is a significant difference between the reduction in attenuation of earmuffs worn with half masks for complete with particle filters because they may be equipped with different kind of the head strap. Med Pr 2017;68(3):349-361 Key words: hearing protectors, earmuffs, sound attenuation, respiratory protective devices, full face masks, half masks Wstep: W srodowisku pracy pracownicy oprocz halasu moga byc narazeni na dzialanie innych czynnikow szkodliwych, dlatego nosza jednoczesnie ochronniki sluchu i inne srodki ochrony indywidualnej. Celem badan bylo okreslenie, czy jednoczesne stosowanie nausznikow przeciwhalasowych i sprzetu ochrony ukladu oddechowego moze wplywac na tlumienie dzwieku nausznikow. Material i metody: Badania przeprowadzono w warunkach laboratoryjnych, wykorzystujac subiektywna metode REAT (Real Ear Attenuation at Threshold--tlumienie dzwieku na podstawie progu slyszenia) oraz obiektywna metode MIRE (Microphone in Real Ear--mikrofon umieszczony w uchu). Za pomoca metody REAT wyznaczano tlumienie dzwieku nausznikow przeciwhalasowych. Metode MIRE wykorzystano natomiast do wyznaczania zmiany tlumienia nausznikow pod