Acoustical design options for noise control and improvement of speech intelligibility: Dokuz Eylul University Hospital Emergency Department Unit

The aim of this thesis is to put forth acoustical design guidelines to control indoor noise levels and improve patient – staff comfort and well-being in Dokuz Eylul University Hospital, Emergency Department. The patient care areas in Dokuz Eylul University Hospital, Emergency Department are open planned, crowded areas with many reflective surfaces (marble floors, ceramic tiles etc.) and it houses many noise generators (alarms, medical equipments, public address systems etc.). The noise levels in these areas are far from the ideal values presented by World Health Organization. It has been documented with various studies that such noise levels are known to have degrading effects on patient's curing process, causing anxiety, stress and various health problems. On the other hand, high levels of indoor noise are documented to cause low performance, lack of concentration and communication problems between the staff. That is why noise control in hospitals, which are sensitive working environments, has become mandatory for both the patient's and the staff's well-being. In order to achieve this, noise level measurements have been carried out in 3 areas, which are defined as the noisiest, for 48 hours each. For the noise level measurements, a sound level meter which complies with international standards, NTI Audio, XL2 model has been used. The results have been classified as the noisiest hours and average noise levels for each measurement area. In the next phase, the ER service has been modeled in 3D in order to evaluate the soundscape and apply acoustical designs for noise control. The acoustical conditions of the service as it was measured (surface materials, noise levels etc.) have been implemented on the model so that previously measured average noise levels have also been achieved on the model. Additionally reverberation time and speech intelligibility data have been gathered and evaluated. In the final phase, acoustical designs have been made in order to provide acceptable levels of noise control and speech intelligibility. The results and the new acoustical conditions have been compared and the most successful acoustical design has been determined. The conditions before and after the acoustical design have been evaluated with audio convolutions. In the final phase, a listening test consisting of 20 participants have been organized to evaluate objective parameter – subjective preference relationships.