“The care in day surgery was excellent however there is a lot of noise from the clinics which are positioned right beside day surgery where patients are either waiting for surgery or recovery post operation,” wrote one (unidentified) complainant about their experience in Broome Hospital on the Patient Opinion web site.
“I felt I couldn’t properly recovery after my surgery due to the constant chat and noise from the clinics directly beside day surgery. There seems to be a lot of people traffic and constant noise due to two clinics which are beside a day surgery unit, which I think is inappropriate for patients recovering from surgery.”
That patient is not alone in his/her frustrations. In 2005, a study by the Journal of Acoustical Society of America found that noise in hospitals throughout that country had increased twofold during the day and fourfold during evenings since the 1960s. According to that study, not one out of 35 hospitals studied complied with World Health Organisation guidelines which specify that background noise in hospital patient rooms should be no more than 35 decibels during the day and 30 decibels at night.
This is a serious issue. As outlined in a 2011 White Paper by lawyer Megan Short and Soundmask Australia senior product developer Andrew Pearson, excessive noise has been shown to produce physiological changes in patients, including lower oxygen saturation (increasing need for oxygen support therapy); higher blood pressure, heart and respiration rate; and compromised sleep. This leads to sleep loss, slower recovery times and greater likelihood of readmission. Noise also impacts privacy and doctor/patient confidentiality.
Noisier environments also impact staff, which can in turn affect performance through dispensing errors (as directions are more difficult to understand), diminished concentration and cognitive function (through distracting noise) and lower productivity because of physiological effects.
In a recent AECOM survey of hospitals, health departments, hospital operators and designers, 60 per cent raised sleep disturbance, noise from nurses stations and acoustic reverberation as an issue whilst 40 per cent mentioned privacy for consultations, 30 per cent mentioned sound transfer from corridors to wards, and 30 per cent mentioned café noise.
How can noise be controlled? AECOM associate director, acoustics team leader, Victoria, Danny Boglev and John Cooper, associate director – acoustics at acoustic and vibration consultancy Resonate Consultants offer some insights on how to manage noise regarding the interior elements of hospital acoustics.
According to Cooper and Boglev, noise must be controlled from various sources. These include staff stations, corridors (conversation, trolleys and so on), monitoring equipment (such as beeping alarms), high activity zones such as emergency departments, and external noise (road traffic, helicopters and so on). Staff stations, Boglev says, are increasingly decentralised and located within wards. This means noise from conversations can be overheard within rooms. Emergency departments are particularly important, he adds, as people in this area are already under stress and an unduly noisy environment could exacerbate this.
Before measures within individual rooms are taken, it is first important to think about overall hospital layout. On this score, Boglev says areas which are sensitive to noise need to be isolated from those in which high volumes of noise are frequently emitted. The former category of areas includes emergency departments, intensive care units, neo-natal wards, and treatment rooms. The latter includes helipads, medical imaging rooms and plant rooms. It can be disconcerting, Boglev says, to be waiting to go into surgery or in the emergency ward and to overhear other patients who might be in stress.
Cooper says patient rooms should ideally be situated on small ‘side-shoots’ rather than next to main corridors. The new Royal Adelaide Hospital, for example, has all patient rooms located in side corridors. Whilst this is primarily being driven by infection control considerations, it does free patients from noise associated with other patients and from main corridors. To avoid having excessive noise levels outside the doors of one or two patients, staff stations should be kept relatively small.
Boglev says the importance of embedding acoustic decisions into layout decisions should not be underestimated. Where acoustics are left to be dealt with room by room, he says this can necessitate measures such as thicker walls than would otherwise be the case. Apart from not generating the same results that would be achieved were these measures to be complemented with optimal layout arrangements, such measures consume space and add unnecessarily to cost.
Obviously, however, considerations surrounding acoustics must be balanced against other layout considerations such as physical hospital requirements.
Beyond layout, Cooper and Boglev say several measures can be used. In the ceiling, infection grade sound absorbing ceiling tiles are now readily available and there is no reason why these should not be used. Whilst from an infection control viewpoint you would not want to use materials which have a porous space, a number of products are now on the market which are easily cleaned.
Between spaces, correct wall construction with good insulation is essential. Sound absorbent materials which can be applied to the wall and are washable are also useful. Acoustic door seals help to reduce noise entering rooms from corridors.
Often, Boglev says, opportunities for noise control are greater in private hospitals, where acoustic door seals and carpets in the hallways are more common. These measures, he notes, are not often incorporated into public hospitals because of cost considerations. These carpets, he says, reduce noise which bounces off surfaces and reverberates around walls drastically. Sound, Boglev says, is more difficult to control when you have hard surfaces spread around the building.
Cooper is less enthusiastic about carpets. Whilst delivering excellent acoustic qualities, he says these have a significant weakness in terms of infection control.
‘Perfect’ isolation within individual rooms, he adds, is generally not achievable because of the need for staff to be able to monitor patients, he adds.
Nevertheless, he says acoustic seals on the doors can make a significant difference. Also, incorporating lots of acoustic absorption in spaces helps to reduce both the build-up of sound and the travel of sound.
In contemporary hospitals, good sound-proofing is essential for positive outcomes.
With a few simple steps, considerable gains can be delivered.