Mapping the noise in a Greek general hospital

Sound pressure levels were monitored in a general hospital, in Greece, at ten indoor locations and at three outdoor locations, in the yard of the building. The selected indoor locations are representative of distinct activities that are common in every hospital, such as the emergency department, patient wards and several supporting services, like washing the clothes or the dishes. Noise levels were highly variable in each monitoring location and depended on the activities in the room, such as conversations, medical equipment in use, analytical devices or other machinery in operation. The highest noise levels that were recorded were in the blood donation unit and in the laundry room (the L_10,8h was 73 and 79 dB(A) respectively), mainly due to the opening/closing of the metal lids of garbage bins in the first location and due to the wringing of the clothes in the second. Indoor background noise levels i.e. the L_95,8h values, were more than 55 dB(A) and higher than the respective outdoor values (except of the L_95,8h in one ward of the paediatric ward). The calculated average L_{EX, 8h} was 69.3 dB(A), below the European Union lower exposure action limit value, i.e. 87 dB(A), that was set to prevent hearing loss of the employees. However, noise levels in the wards, in the emergency and the outpatient department were above the values suggested by international guidelines for a healing environment. Sound spectra revealed peaks in frequencies that were representative of the sources of the noise and also the presence of low frequency noise components.