A sound argument for a change in thinking

It’s easy to overlook the importance of acoustics within hospitals, where patient care is necessarily focused on the critical and urgent, yet the facts are undeniable — good acoustic design in hospitals improves patient outcomes. Hospitals are inherently noisy places. Elevated noise levels come from a variety of sources: alarms, medical equipment, conversations, music, tannoy announcements, trolleys being wheeled down hallways, and mechanical systems like ventilation and heating.

The impact on patients of consistently being subjected to increased noise levels is well documented. It can interfere with sleep, cause stress and anxiety, and result in headaches and malaise,¹ all of which can slow recovery and discharge times, and generally impede the healing and care process. We must also consider that the impact on staff may result in poorer patient care. Noisy environments contribute to cognitive overload, stress, miscommunication, and the ability to focus, all of which are essential when making critical decisions in fast-paced environments if we want to avoid medical errors. Excessive noise can mask important verbal communications between staff, leading to missed instructions or unclear orders. In busy environments like operating rooms or emergency departments, ambient noise levels can also drown out the sounds of alarms and equipment signals, potentially delaying responses to urgent situations. A well-designed acoustic environment can improve patient safety.

Effective acoustic design techniques

There are a range of techniques that can be implemented to improve acoustics. These may include increasing the sound insulation performance of barriers — including walls, ceilings, and floors, to control noise transfer between areas. The use of sound-absorbing materials is also key to controlling reverberation, which reduces noise build-up and enhances communication. Hospitals pose a unique set of challenges, in particular around the issues of infection control and washability, meaning the utmost consideration needs to be given to appropriate materials for the construction and fit-out of hospital interiors.

We must also take into account the control of sources of noise and vibration such as external road and rail traffic, internal building services, or medical equipment such as MRI scanners. This reduces internal levels of noise, promoting rest and relaxation.

Acoustic consultants require a good eye for detail, ensuring that sound proposals are developed for the construction of barriers such as walls and floors, and how building services interact with these elements. Where essential services penetrate through walls, a weakness in the wall is created. Through good planning, the extent of such penetrations can be minimised and mitigated, such that the integrity of the wall is maintained.

Of course, while when building and equipping new hospitals, and modernising existing ones, equipping them with latest technology and minimising their energy consumption are both key, it’s equally important that they operate efficiently and give patients the optimal care.

New-build and refurbishment projects undoubtedly pose different challenges when it comes to the acoustics of the environment. The design of new-build schemes involves many parties and stakeholders, and the development of departmental zoning can often be focused understandably on operational efficiencies. It can be hard to zone noisy departments away from quieter room uses such as consultation rooms or single-bed recovery wards. Where possible, buffer rooms or zones (such as storerooms) can be used to separate zones and minimise the acoustic impact.

Lighter weight materials

Modern building constructions commonly utilise advanced, lighter weight materials for structures and facades, which are more energy efficient and reduce embodied carbon. Lighter structures generally perform worse from a sound insulation perspective, which can be challenging when locating spaces such as MRI or PET scanning rooms, with louder activities.

Over time, and with the development of new technologies, the need for specific rooms within a hospital changes. In recent years, we have seen a dramatic increase in the need for ward space, while flexible working patterns post-COVID have resulted in a reduced need for administrative workspaces. As a result, change of use is becoming more and more common. However, the acoustic requirements may be vastly different, so we must ensure that these considerations are addressed at an early stage of the project to ensure the best outcomes for patients and staff.

Modern Methods of Construction may not be viable due to the inherited limitations of the existing building. Listed building status may result in the retention of single glazing, or old treatment rooms may be repurposed for videoconferencing and remote consultation. At CPW we appraise existing spaces to develop practical solutions that allow staff to carry out their important work.

Early engagement of acoustic consultants in both new-build and refurbishments ensures that both sustainability standards and local authority requirements are met, while creating a calm and privacy-conscious acoustic environment, avoiding the need to re-design for acoustics at a later stage, which can be both costly and time-consuming.

Acoustics under the microscope

CPW was involved in one such project at the Princess Royal Hospital in Telford, part of the Shrewsbury and Telford Hospital NHS Trust. The theatre and day case conversion works involved the refurbishment and extension of the existing building to provide new operating theatres and recovery wards. The area of the building being refurbished was not originally intended for such use, and rooms were located directly below the roof void without a structural floor for partitions to be constructed up to. This raised significant challenges around noise transfer between rooms via ceilings and the ventilation systems within the roof void, bypassing separating walls.

A combination of enhanced ceilings, void barriers, duct lagging, and cross-talk attenuation, were used to mitigate noise transfer that would not typically be present within a new hospital, where full-height partitions and solid concrete floor slabs provide robust forms of noise control.

Existing hospitals commonly have significant limitations upon space, and on this project it was necessary to construct a new extension using minimal structural mass, to include new recovery rooms and a building services plant room located directly above the recovery rooms.

Good departmental zoning in new-builds would normally avoid this kind of adjacency — to reduce the risk of elevated noise within the patient rooms, as well as minimise design complexity. However, for the theatre and day case conversion works this was not an option. A mass barrier plasterboard ceiling was introduced below the lightweight structural floor, and above the room-facing modular ceiling and services zone. A plasterboard mass barrier ceiling is an effective way to improve the acoustic performance of a floor without introducing significant mass to the structure, but leads to complications with services zones and the construction of partitions, particularly any supports for moveable walls.

By employing good acoustic design, CPW developed solutions within the constraints and limitations of the existing building. Through this design, noise levels were controlled within recovery rooms and wards, with the aim of reducing disruption and stress, and thus promoting rest and relaxation. This more calming environment improved sleeping conditions, allowing patients to recover faster and more effectively.

The impact of volume control

When in hospital, patients are not only incredibly vulnerable, but often need to share intimate details, often in a public environment. By addressing the acoustics of the space, we were able to provide increased privacy control, giving patients greater confidentiality and dignity, and reduced anxiety around being overheard or disrupting others.

Addressing noise disruption paves the way for clearer communication, allowing staff to convey important information, especially during critical moments, reducing the likelihood of errors. This means patients can be treated more efficiently. By managing noise more effectively, staff can better concentrate on their job, with less stress and enhanced job satisfaction. Through these positive effects, quality acoustic design can boost the operational efficiency of departments, improving the quality of work, and enhancing staff and patient welfare.

Although they may not always be a primary consideration, acoustics can play an important role in creating a positive healing environment in hospitals and other healthcare facilities. By reducing noise pollution, enhancing communication, and improving overall comfort, thoughtful acoustic design can have a profound impact on both patient outcomes and staff performance. Hospitals that prioritise acoustics in their design will foster environments that are more conducive to healing, safety, and satisfaction for everyone within their walls — and what better time to address this noise issue than while we are already focused on making improvements to our hospitals to meet Net Zero carbon deadlines?

The future of acoustic design in healthcare

As capital investment in healthcare increases, new technologies and instrumentation will be adopted. Older facilities may be refurbished to include modern imaging scanners such as PET or MRI scanners. It will accordingly be necessary to suitably modernise the internal structures to adequately control noise and vibration, such that the modern equipment doesn’t jeopardise the use of surrounding hospital areas.

Emerging technologies may assist in providing greater opportunities for acoustic design, such as the use of noise cancellation. In loud areas or areas where the demands for hygiene and safety (two-way doors for example) override the ability to utilise acoustic ceilings or doorsets, noise cancellation technologies could be developed to create more peaceful spaces.

The push for Net Zero carbon in the NHS has resulted in an urgent programme of new build and modernisation work in healthcare, in particular given that NHS emissions currently equate to 4% of England’s total carbon footprint.2 Commendable and necessary as it is to reduce our impact on the environment, it’s imperative to ensure that patient wellbeing remains the top priority.

NHS Trusts throughout the country are removing old gas boiler heating systems and replacing them with electric alternatives such as air source heat pumps. Due to their nature, heat pumps need to be located externally, and can form a significant new noise source located close to existing healthcare buildings. Without due care, such equipment can undermine internal conditions. By adopting a holistic approach to the M&E design at CPW, we are able to advise Trusts upon the best approach to developing their decarbonisation strategy.

Where opportunities to improve environments for patients and staff present themselves, such as through acoustic design, we must embrace these. The current influx of healthcare improvement works to meet the Net Zero carbon deadline provides the perfect opportunity to address acoustics as part of the required M&E works.

References

1 Eijkelenboom A, Bluyssen PM. Comfort and health of patients and staff, related to the physical environment of different departments in hospitals: a literature review. Intelligent Buildings Journal International 2022; 14(1): 95-113.

2 Applying net zero and social value in the procurement of NHS goods and services. NHS England. 23 March 2022. https://tinyurl.com/3uvft4x5