Our previous two articles on noise pollution in hospitals and healthcare can be found here (Part 1) and (Part 2). In this third and final article, we cover the solutions to these problems.
The acoustic ABC principles – “Absorb”, “Block” “Cover” – are a useful way to consider reducing noise pollution. For example, sound can be absorbed by acoustic panels, single rooms block more noise than curtained multi-patient rooms, and acoustic sound masking covers noise with ambient sound. If all three elements are incorporated into healthcare design, many of the problems of noise pollution will be reduced if not eliminated.
However, preventative measures like behaviour modification are just as important when addressing noise pollution.
Behaviour modification
Modifying staff behaviour can have a positive impact in respect of noise pollution. Reducing noise pollution can be as easy as reducing PA paging or sending silent messages, training staff to converse quietly or closing doors before conversing.
Simple changes like wearing soft-soled shoes, replacing noisy materials with quiet materials – for example plastic rather than metal bins – and padding medical chart holders can all decrease noise. Similarly, turning off unnecessary alarms or at least answering all alarms quickly can reduce noise pollution and eliminate a major source of sleep loss and patient discomfort.
Staff training can also focus on awareness of noise – for example, encouraging an attitude where squeaky doors are noticed and fixed, unnecessary equipment is switched off and ring tones are set to vibrate. Some hospitals have a “quiet time” protocol where medication schedules are adjusted to avoid waking patients and noise monitoring devices like traffic lights alert staff when noise is too loud – encouraging them to speak softly at night.
Personal noise reduction or noise cancellation devices
Provision of ear muffs, ear plugs and noise cancellation headphones can assist patients reduce the effects of noise. Studies conducted in respect of ear muff and ear plug use concluded that patient sleep improves in noisy hospital environments when such devices are used. Even during times of rest, not sleep, distracting noises like snoring and low-frequency noises can be significantly reduced with noise cancelling headphones.
Acoustic treatments
Various acoustic treatments can assist with reducing reverberation and noise transfer. Panels and other absorptive materials, door seals, low-reverb flooring and wall coverings can all assist in absorbing or blocking noise pollution. Similarly, eliminating or minimising reflective surfaces can assist to reduce reverberation when noise does occur. In studies where high performance sound-absorbing ceiling tiles were used, patients slept better, were less stressed and reported greater satisfaction.
However, it is important that bacteria-resistant materials are used, as traditional sound absorption materials often fail to meet hospital requirements in respect of ease of cleaning, bacteria resistance and flammability.
Sound masking in hospitals
Acoustic sound masking is the “Cover” of the acoustic ABCs, and on its own can solve many of the noise pollution problems – a boon for cost effective retrofits. For example, a recent literature review found that sound masking has the most significant effect in promoting ICU patients’ sleep compared with acoustic absorbers, earplugs/earmuffs or behavioural modification.
There are additional advantages to acoustic sound masking, specifically energy efficiency and speech privacy. For example, an acoustic sound masking system typically uses a very low wattage, with some systems running through a whole hospital with the same amount of energy as one desktop personal computer.
Acoustic sound masking works by generating unobtrusive sound waves. This imperceptibly increases the level of background sound in the space, masking intrusive noise and ensuring that speech is private. The space itself appears quieter because intrusive sound and intelligible speech are masked. It is important to choose a sound masking system that is randomized so that the sound does not become distracting like white noise.
Conclusion
Noise pollution has quantifiable negative effects on healthcare staff and patient recovery, and can impact upon the legal obligations of healthcare facilities. However acoustic sound masking and other acoustic treatments can eliminate or ameliorate these problems in a sustainable and cost effective manner.