en Occupational and Industrial Health Occupational and Industrial Health پژوهشي Original Article <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:times new roman;"><strong>Background:</strong> The present study aimed to replace the integrated sound level meter by the noise map of a work environment in order to estimate the equivalent continuous sound level (L_eq) as an important quantity in the noise monitoring of continuous noise sources.<span dir="RTL"></span><br> <strong>Methods: </strong>In this theoretical-experimental study, the grid method was initially used. Sound pressure level (SPL) was measured at the selected stations in three noisy industrial halls. Data analysis was performed in ArcGIS 10.2 software, and the noise map was plotted for each hall separately. Afterwards, the different zones with various SPL intervals were calculated on each noise map, and L_eq was determined. For the comparisons, L_eq was also calculated using logarithmic equations, based on which the integrated sound level meters were programmed.<span dir="RTL"></span><br> <strong>Results:</strong> The proposed method was highly accurate with the relative error of less than 2%. Furthermore, it decreased the number of mathematical operations 7-15 times compared to the conventional logarithmic method.<span dir="RTL"></span><br> <strong>Conclusion:</strong> According to the results, the available GIS-based software could be accurately replaced by the routine L_eq measurement hardware to estimate the L_eq spatial noise in noisy industrial environments.</span></span></div> Equivalent sound level (Leq), Noise mapping, Geographic information system (GIS), Noise monitoring, Industrial indoor space 50 55 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-140-3&slc_lang=en&sid=1 Faramarz Majidi fma@zums.ac.ir 10031947532846009693 10031947532846009693 No Department of Occupational Health and Safety Engineering, School of Public Health, Zanjan University of Medical Sciences, Zanjan, Iran. Younes Khosravi khosravi@znu.ac.ir 10031947532846009694 10031947532846009694 Yes Department of Environmental Science, School of Science, University of Zanjan, Iran. kamalad-Din Abedi kamal.abedi@gmail.com 10031947532846009695 10031947532846009695 No Environmental health research center, Kurdistan University of medical sciences, Sanandaj, Iran.