Acoustics in Hospitals
Hospitals have always been given the perception that is should be a quiet place. Since young, we are taught to not make too much noise or speak too loudly in the hospital. Here’s a quick question to you: Do you really think that the hospital is THAT quiet?
We’ll get back to that shortly.
Since start of the COVID-19 pandemic, hospitals have been widely used for testing and treating patients. Everywhere you go, you will hear about how packed the hospital is, and how they are running out of medical facilities to accommodate for the patients. This also means that the hospitals are now very crowded as compared to the normal days, leading to inevitable noise.
Even during pre-COVID days, hospitals are known as an anxiety-inducing environment naturally, giving patients some nerve-wrecking feelings when then enter the building. Aside from being nervous about the treatment that they may be undergoing, the key reasons that lead to that environment is due to the acoustics design of hospitals. Normally, hospitals have hard sound-reflective surfaces with the intention of using materials that can be easily cleaned and disinfected frequently. At the same time, the noise that can often be heard in the hospitals include people walking, talking, phones ringing, machines and instruments beeping/humming, medical staff rushing pass the walkway, emergencies calling etc. Imagine having all these sounds happening almost at the same time, with the highly sound-reflective condition. Not too pleasant, is it?
Noise limits in hospitals
In Malaysia, the recommended permissible sound levels (LAeq) in noise sensitive buildings like hospitals are 60 dBA in the day, and 55 dBA at night.
Here are also some guidelines and standards set for countries in Europe:
- Sweden: Reverberation time ≤5 seconds
- Norway: Reverberation time ≤4 (Class A), 0.5 (Class B), 0.6 (Class C), 0.8 (Class D) seconds
- Finland: Reverberation time ≤8 seconds; Speech Transmission Index ≥ 0.6
- Denmark (Design guideline, not mandatory): Reverberation time ≤6 seconds
- France: Reverberation time ≤8 seconds
- Poland: Reverberation time ≤8 seconds
- Spain: Absorption area related to room volume ≥2
- Germany: Absorption area related to room volume ≥25
- United Kingdom: Absorption area related to floor area ≥8
From the information above, it is clear that different countries have their own regulations to follow. Some focuses on reverberation time; others look at the absorption area in m2 related to the room volume or floor area. Of course, these standards and regulations on acoustic standards do have positive impact to the healthcare facilities, but it is still important to think of better ways to improve the acoustics in hospitals.
Benefits of noise control in hospitals
Studies have shown that by controlling the noise inside the hospitals to a correct level, many benefits can be achieved, especially to the advantage of patients. For example:
- Higher confidentiality and comfort
- Lower staff turnover, fatigue, and stress
- Better customer/staff satisfactory rates
- Improved patient recovery times
- Lower medical/communication errors
A study was done in the waiting areas of two hospitals in Kuala Lumpur, Malaysia to clarify the actual acoustical conditions respectively. Through measurements, it was found that the noise levels for both hospitals were highly affected by the noise coming from general activities in the waiting areas, in fact causing the noise levels of both waiting areas to exceed the recommended noise level. A survey was also carried out in the same study to find out the perceptions of respondents regarding the noise nuisance during their waiting time in the waiting area, in which the survey results also supported the measurement results.
In the UK, the NHS Inpatient Survey found that 40% of hospital patients are bothered by noise at night, with noise levels over 100 dB being measured in the intensive care units (ICU). At such a noise level, it is almost impossible for patients to enter deep sleep, and even worse, it is beyond the point where hearing damage starts to happen. Excessive noise can also cause annoyance and fatigue to patients as it affects sleep quality and the quality care being received.
The loud and noisy environment in hospitals not only will cause patients to be vulnerable to stress and anxiety, it will also impact the communication between doctors and nurses and the patients. Therefore, it is imperative that the health and well-being advantages of effective acoustic treatments and designs should be made the key focus for any upcoming new hospital projects, be it a newly built one or in refurbishments.
Acoustic treatments in hospitals
As listed above under the guidelines and standards section, there are a few aspects that can be looked at to improve the acoustic environment in the hospitals. Many of them are related to the construction side, such as windows, doors, sound insulation, sound absorption, sound proofing and other external noise factors.
Since we have known that hospitals have a very reverberant environment due to the hard surfaces being constructed, let us focus on sound absorption.
Typically, sound absorption is the main solution that can be considered to treat a highly reverberant room. Sound absorbing acoustic panels are the most used treatment to be installed onto walls or ceilings. This is particularly suitable for places like waiting halls or areas where deep cleaning is less of a priority because this is a highly effective solution that can drastically improve the acoustical performance of a space. Not only that, but it will also improve the speech clarity, which helps to make announcements, conversations among individuals much clearer.
Another way to treat hospital noise is through sound masking, which also means to add sound into a space rather than removing it. It may sound contradicting, but actually sound masking is a specifically tuned ambient noise that is designed to reduce the perceived loudness of other noise within the same environment. This method has been popular in recent years especially within the healthcare environments. There are studies showing that patients can get better sleep quality when they are in rooms with proper sound masking systems being installed, as it will mask off the disruptive noises such as instrument beeps or calling tones.
In a nutshell, the acoustics of hospitals should be given more attention to. As a long term effect, it will definitely help to increase the overall satisfaction of the relevant stakeholders of the hospitals, thus improving the inpatient-experience of patients.
Acoustic standards in hospitals – overview and thoughts. (2020, March 23). (Ecophon) Retrieved from Acoustic Bulletin: https://www.acousticbulletin.com/acoustic-standards-in-hospitals-overview-and-thoughts
Acoustique, D. (2021, May 18). How to reduce noise in hospitals with acoustic design? [Case Study]. Retrieved from Delhom Acoustique: https://acoustique-delhom.com/how-to-reduce-noise-in-hospitals-with-acoustic-design-case-study/
Din, N. C. (2013). Evaluation and Analysis of Noise Levels in Hospitals: A Premilinary Investigation. 20th International Congress on Sound & Vibration (pp. 1-8). Bangkok: ICSV20. Retrieved from http://eprints.um.edu.my/13442/1/full_paper_393_20130316104653632.pdf
Environment, D. o. (2019, December). Guidelines for Environmental Noise Limits and Control (Third Edition). (Third Edition). (A. &.-A.-D. Malaysia, Ed.) Federal Government Administrative Centre, Putrajaya, Malaysia. doi:ISBN 978-967-9795-38-7
Irwin, M. (2021, February 8). Hospital Acoustics: The impact of noise on healthcare. Retrieved from Resonics: https://resonics.co.uk/hospital-acoustics-blog/
Written by Khei Yinn Seow
Posted on July 13, 2021