News - May 2018
Healthcare facilities should provide a therapeutic environment where the overall design approach contributes to the process of healing, rather than simply being a location where healing takes place.
However, as hospitals have become busier, with more patients, more staff, more visitors, and a wealth of technology; noise levels have greatly intensified.
“It has been reported that hospital noise levels have increased by 5dB per decade - with some recorded noise levels actually exceeding the recommended maximum,” explains Matthew Sexton, commercial sector market manager at British Gypsum.
“This, combined with the fact that many hospitals are designed and built with hard, sound-reflecting surfaces, means acoustic conditions are made worse as these enable noise to reverberate over large areas and into patient rooms.”
A study conducted by Busch-Vishniac et al in 2005 found that sound pressure levels have risen significantly and consistently since 1960.
On average, daytime levels have risen 0.38 dB and night-time levels by 0.42 dB year on year.
The best defence
Noise pollution of this kind is known to have a severe impact on patient health and wellbeing, elevating psychological and physiological stress, which can be indicated by anxiety, annoyance and even physical symptoms such as increased heart rate and raised blood pressure.
Prolonged loud noises can also lead to memory problems, impaired pain tolerance, and perceptions of isolation.
In one study, heart-attack patients exhibited higher pulse amplitudes in a poor acoustic environment than in a good acoustic environment, i.e. a room with sound-absorbing surfaces, at night-time, when background noise tends to be lower, making noise disturbances more noticeable.
As well as affecting patients; noise can also have a detrimental impact on staff as patient care teams need to be able to understand and quickly respond to auditory signals, for example conversations, medical equipment, and alarms.
In addition, the speech recognition systems now commonly used in healthcare environments rely heavily on appropriate speech signals to operate.
The best defence against noise is to ensure that proper precautions are taken at the design stage and during the construction, or redevelopment, of a building.
“As there are many acoustic design factors that need to be considered, it is highly recommended that specifiers liaise with a reputable manufacturer early in the design process to ensure the correct acoustic solution is specified for each area of the building,” said Sexton.
One of the most-effective ways to provide sound absorption is to install acoustic ceiling tiles or boards to control reverberation.
Sexton said: “Noise from a room may pass through the dividing element and the surrounding structure, so it is vital that optimum acoustic solutions are specified and detailed to ensure you get maximum performance.”
Among the guidance on the subject, the US Ceilings & Interior Systems Construction Association (CISCA) has published the document, Acoustics in Healthcare Environments¹.
The white paper acts as a free tool for architects, interior designers, and other design professionals worldwide, giving an introduction to acoustical issues commonly confronted on healthcare projects.
The document calls for the appointment of an acoustical engineer and ‘appropriate finish selection’, advising: “Site design can have a major impact on acoustics in healthcare settings.
“Determining what spaces will be adjacent to each other and how the space should be laid out takes careful consideration of how specific areas are going to be used, the level of privacy needed, and the desired background noise level, among other factors.”
A spokesman for manufacturer, Ecophon, added: “It’s important to consider the overall space - how large it is, what shape it is, and what materials have been used. Then you need to consider how that affects the sound environment and can anything be changed.
“You also need to consider the people using a building.
“We are all affected by noise, but many users of healthcare spaces have additional requirements, such as babies, elderly people, people with hearing loss, and those with dementia, who are sensitive to sound, and determine their requirements from the room acoustics.
The right solution
“Finally, ask is it a space where quiet will benefit the users or where privacy is key, or maybe it is a space designed to be more interactive. Then ask whether the room design and finishes can help promote this purpose.
“From this you should be able to establish the type of products required. Generally, these will either absorb sound, stopping it reflecting; or reflect sound, stopping it transmitting to an adjacent space.”
John Spicer, technical sales manager at Armstrong Ceilings, adds: “It is almost impossible to add sound absorption to low-level surfaces within hospital spaces because of the strict cleaning regimes and the need for imperforate and seamless surfaces to aid cleaning and create a durable, practical space.
“That means the ceiling plane is the perfect location to add this sound absorption; and metal, as well as mineral, tiles can meet this requirement.
“Acoustic ceiling tiles with antimicrobial treatments help to control contamination and their robust surfaces allow strict cleaning regimes to be followed without them sustaining damage.
“Choosing the most-appropriate product for an area is also a key task as the balance of acoustical performance, durability, infection containment and control, as well as accessibility, is critical.”
It is these important factors that are behind the development of the latest healthcare acoustic surface solutions and the drivers for specification.
“When selecting products for acoustical performance; it is important to understand the type of performance required,” said Spicer.
“High sound absorption may be required to control the reverberation within a ward or open space, but there may also need to be some sound attenuation or sound blocking to mask noise from floors above or from adjacent rooms or services within the void.
“Health Building Note HBN 00-10 Design for flooring, walls, ceilings, sanitary ware and windows should also be consulted to understand the category of the room and the finish required.
“A compromise on the acoustical performance may have to be made to accommodate all of these requirements, particularly in clinically-specialist areas.”
Acoustic solutions have been developed for most surfaces, primarily internal partitions, wall linings, floors and ceilings and fire protection partitions.
Armstrong’s Bioguard Acoustic tiles are an example of the very-latest ceiling solutions and are widely used in health and care environments, as is Ecophon’s range of sound absorbent ceiling and wall panels solutions; and British Gypsum’s Gyptone, Rigitone and Gyprex boards.
The impact of these is covered in British Gypsum’s dedicated White Book Health Sector Guide for specifiers.
Sexton said: “When applied to room surfaces or objects, sound-absorptive materials reduce the reflection of sound that strikes them, which helps to make a space seem less ‘echoey’ or, more technically, less reverberant.
“The ceiling plane is often the only one of substantial size, and relatively unobstructed, where sound absorption can be introduced.
“However, sound-absorptive materials are most effective at controlling reverberant sound when distributed between several room surfaces or objects rather than just being applied to one.”
Moving forward, Sexton envisages products further developing to meet the continuing priorities within the health sector.
He said: “New technologies will further improve self-cleaning/easy-clean surfaces with antimicrobial performance, while also improving sound absorption and attenuation.
The evolution of products for healthcare will follow all requirements, both acoustically and practically without compromise.”
The Ecophon spokesman added: “Hospitals are becoming busier and noisier and so products will continue to be required and to evolve.
“The requirement for cleaning and decontamination is always a key consideration and will continue to be so alongside a requirement for more-robust impact-resistant finishes.
“The link to Biophilic design may also result in more nature-based solutions within soundscaping and the use of colour and visual images on acoustic products.”