Noise and Room Acoustic Conditions in a Tertiary Referral Hospital, Seoul National University Hospital

Cho, Wan-Ho; Jeong, Cheol-Ho; Chang, Ji-Ho; Lee, Seong-Hyun; Park, Moo Kyun; Suh, Myung-Whan; Han, Jae Joon

thetic device, which was known to be relatively noisy due to surgical drills and suctions. The measurement started after changing to small drills (posterior tympanotomy), and it was 59.3 dBA. The second surgery was a canal wall down mas-toidectomy, where large drills and suctions were used, and the average noise level was 62.5 dBA. Lastly, an intact canal wall mastoidectomy was measured, which was regarded as a quiet surgery. Particularly, the measurement started after drilling, so the noise level was lowest as 57.4 dBA. In summary, the main noise sources in these three surgeries were small drills, large drills, and suctions with noise levels of 59.3, 62.5, and 57.4 dBA, respectively. The background noise was measured to be 49.2 dBA. In the examination room, the noise from medical devices varied between 55 to 65 dBA during examinations. The sound transmission between the examination rooms was not measured but one could hear noise from the adjacent examination room. The background noise including the construction heating, ventilation, and air conditioning noise was 49.6 dBA, which is as high as in the operating room. The nurse station was pointed out by the staff to be noisiest in the questionnaire in Fig. 4 . The measurement confirmed this statement; the noise level at the nurse station ranged 58-64 dBA in several measurements near wards, examination rooms, and children department, which was even noisier than in ERs. The highest level measured was 64.1 dBA at a nurse station that also functions as a reception (Fig. 2C) , and the second highest value, 62.4 dBA was measured at a preparation room when a sterilizer is running (Fig. 2D) . Except for these values, the noise level ranged 58.0-62.2 dBA.