effects of various frequency noise exposure on ambulatory blood pressure in control room operators Download PDF

Purpose: Noise is a potential source of stress for people and can cause non-auditory effects. The aim of this study is to find the effect of the quality, independent of quantity, of any type of noise on blood pressure and to investigate some of its non-auditory effects. Settings and Design: This experimental study was carried out on 60 staff of petrochemical control rooms. Each subject, filled a GHQ screening questionnaire. The experiment was carried out in a measuring room that conformity by OSHA 1910.95 App D. Eight types of noises were used: white, blue, pink noise and noise in 125, 500, 1000, 2000, 4000 Hz frequency with flat-frequency character. Methods and Materials: The level of sound pressure in A-weighted of both noises was below 75 dB. Subjects completed noise sensitivity questionnaire. Blood pressure was measured by a digital blood pressure-meter before and after noise exposure. Statistical analysis used: Then the statistical analyses were performed using the SPSS software. Results: Result showed that there was a significant difference in systolic blood pressure by the exposure to base noise and all of 8 noise types (p<0.005), except for white noise. Noise exposure had the most noticeable effect on systolic and diastolic blood pressures by SPL 65-75 dB(A) in leader frequency 1,2 kHz. Noise annoyance in 1, 2 kHz was more than other types of noise exposures. Conclusion: These results imply that blood pressure and noise annoyance are more sensitive to some types of noises, as noise exposure by SPL 65-75 dB(A) in leader frequency 1,2 kHz.