HealthCare Acoustics

By Dr Mohd Zamri Jusoh

Unhealthy acoustic environment in hospital can affect patient’s recovery. Any excessive sound sources that come from the surroundings might affect patient’s sleep pattern, increasing stress and less tolerance to pain and healing process. Hospital should be the most quiet public place and so peaceful. Since it is a place for healing process, it is important to be perfect acoustically to provide good healing environment. One important area, which is, Healthcare Acoustics can help the hospital to be the perfect place for healing and help the patients enjoy the treatment until they are cured completely. The sources of sound energy in hospital are from the occupants, hospital’s equipment and also come from other environment such as the nearby roadway, noisy air ventilation, generator and even the renovation and construction job. Generally, the building design can affect the noise level (Stichler J.F et al., 2001). In several studies ( Hodge B et al., 2008, Tsiou C. et al., 2008, Healy A.N. et al., 2007, Christensen M. et al., 2004, Shankar N et al., 2001), some noise sources in the operating room were identified caused by the trolleys movement, doors opening and closing and also the metal tools handling by the medical staff. Any exposure to excessive unhealthy acoustic environment might affect patient’s memory, high level agitation and less tolerance to pain (Alison E. et al., 2001). At noisy places also can produce less effectiveness to the medical staff. An ideal place for the patient to relax, that not exceeds the sound level of 35dBA (Alison E. S. et al., 2001) which is the noise level recommended by World Health Organization (WHO). Any operating room with more medical equipment can produce sound level up to 50-75dB (Hod ge B. et al., 1990). To assure the patients satisfaction and help the recovery and healing process, it is important to improve the noise level in every place in the hospital. However, each place contains different function and requires specific acoustic solutions. Common important places in the hospital are the Intensive Care Unit (ICU), consulting room, ward room, operating room, reception and admission area and also the corridor.

Intensive Care Unit (ICU)-This is the most sensitive area since patients will have extra care and monitoring by medical staff. Speech intelligibility is important to assure effective two-way communication between the medical staff to avoid any error. The quietness can help the medical staff to support and detect any calls from the patients and handle the patient needs.

Hospital Consulting Room-Speech intelligibility is the main focus in this room for both patient and the medical staff. Confidentiality is important during the consultation process.

Ward Room-This place should offer quiet and peaceful place to patients to endure their healing and recovery process. Since the recovery process may take a long period, the area should provide the patient’s privacy and proper rest at the highest level. However the selection of the sound insulation material in this place is critical to avoid the building component to house germs and viruses and cause more problems to the patient.

Operating Room-Two way communications is vital in this room to avoid miss-communication that can guide to fatality. The quietness of the area can give a relaxation to the patients thus eliminate the stress level so that the patient and the medical staff can go through the operation process accordingly.

Reception and Admission Area-This is the busiest place in the hospital. This area is heavily crowded by patients, medical staffs and also visitors. To reduce the stress is important in this place since this area need to support good guidance and communication to the occupants.

Corridor-The sound generated by the occupants along the corridor may interrupt and disturb other areas in the hospital.

As shown on Table 1, most of the areas in the hospital are recommended to be as low as 40 dB except in ward area for 35 dB since this place require good aural environment to support good rest and sleep for the patient ( Yang T.K. , 2011).  The recommended reverberation time is between 0.4s to 0.7s for most areas in the hospital.

Type of facility/ occupancy	Recommended design sound level (dB)		Recommended reverberation time
	Satisfactory	Maximum	T (s)
Intensive care wards	40	45	0.4-0.6
Consulting Rooms	40	45	0.4-0.6
Wards	35	40	0.4-0.7
Operating theatres	40	45	Based on specialist advise
Reception and waiting areas	40	50	0.4-0.7
Corridors	40	50	0.4-0.6

Table 1: Recommended Design Sound Levels for several areas in Hospital Buildings

        ( Australian/New Zealand Standard^TM AZ/NZS 2107:2000)

 A good hospital acoustic can assure the effectiveness of the hospital and can offer such an ideal place for patient to heal and recover their injuries or diseases. However the selection of the material of the building component is also important to provide best HealthCare Acoustic for each type of facilities in the hospital. This can be achieved through proper design and specification during the planning and designing process.

References

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2.     Alison E. S., Ken T. S., Holdgate A., Ahern N. et al., Noise Level in an Australian emergency department. Australian Emergency Nursing Journal 2001 ; 14, pp 26-31

3.     Hasfeldt D., Laerkner E., Birkelund R., Noise in the Operating Room- What Do We Know? A Review of the literature. Journal of Perianesthesia Nursing 2010; vol 5, pp 380-386

4.     Hodge B. , Thompson J.F., Noise Pollution in the operating theatre. LANCET 1990; vol 335, pp 891-894

5.     Tsiou C., Efthymiatos G., Outanji M., Noise in the operating rooms in Greek hospitals. Journal Acoustic of Social Am 2008; vol 123, pp 757-765

6.     Healy A.N., Primus C.P., Koutanji M., Quantifying distraction and interruption in urological surgery. Quality Safety Health Care 2007; vol16, pp 135-139

7.     Christensen M., Do hospital personnel influence noise level in an operating theatre and a postanaesthesia care unit? . Journal of Advance Periop Care 2004; vol2 ,pp19-26

8.     Shankar N., Malhotra K., Ahuja S. et al., A study of noise levels in the operating theatres of a general hospital during various surgical procedures. Journal of Indian Medical Association 2001; vol99, pp 244-247

9.     Australian/New Zealand Standard^TM. AS/NZS2107 Acoustics- Recommended design sound levels and reverberation times for building interiors. 2000

10.  Xingxian S. , Xin C., Derakshan J., Eagan T., Baig T. et al., The suppression of selected acoustic frequencies in MRI. Applied Acoustics 2010 . Vol 71 ,pp 191-200

11.  Luzzi S. , Falchi S. , Noise Pollution in General Hospital. Journal of Canadian Acoustics Association 2002

 Yang T.K. Acoustics in Hospitals: Key Issues Society of Singapore Newsletter July 2011 ,pp 26-32