The current COVID-19 pandemic has caused a considerable amount of attention to be directed towards mental wellbeing and the effect that our environment can have on it. While this has focused the spotlight on such issues as ventilation, lighting and the proper use of space, it’s easy to overlook another important area – acoustics. Spaces with poor acoustics can make communication and concentration levels difficult to maintain, and this can have an extremely negative impact on the people that use them. This is especially important in the workplace where distracted employees become less efficient and less productive.
Many people underestimate the importance of acoustics in buildings, often because they misunderstand the basic principles involved and fail to appreciate the two most common causes of poor acoustics – reflected sound and noise transference. These processes can both seriously inhibit the creation of effective acoustic solutions, so it’s important to set the record straight if we’re to create comfortable and efficient acoustic environments.
Hearing the problem
Noise transference refers to sounds that originate in one room and then spread to an adjoining space, perhaps via a poorly-constructed separating wall, or by vibrating through a shared building component, such as a beam or lintel. Reflected sound, however – also referred to as reverberation – concerns sound that is generated within a space and then reflects off any hard, impervious surfaces in that space, such as walls, ceilings and floors.
Sounds transferring from one space to another can degrade the clarity and intelligibility of speech, while the ‘blurring’ caused by reverberated sound can add in unwanted flutter echoes that have the same effect. Vowels and consonants are often lost in the general noise of the room. While this can be particularly challenging for people who may already have hearing issues, in some cases, it can even make a space unusable.
When it comes to mixed-use spaces, such as schools, universities and restaurants, the unwanted effects of noise transference or reverberation are obvious. However, they can also have a detrimental impact on less obvious spaces, such as swimming pools. A pool area will generally feature large expanses of wall and ceiling which can reflect sound, as can the surface of the water itself. For this type of application, an acoustic solution must be purpose designed, particularly as it has to withstand the potentially damaging effects of a warm, humid and chemical-laden atmosphere. This illustrates the fact that a comfortable and properly designed acoustic environment must take a very wide range of factors into account.
To avoid noise transference and reverberation problems, designers need to ‘design with their ears’ and make acoustic considerations a key issue right from the start of a project. They should factor in the need to prevent noise transference, and to absorb sounds, echoes and resonances within the spaces where they originate. This requires them to consider the likely acoustic impact that the size, height, volume and shape of their intended design will have. The presence of any hard, reflective surfaces used within the space, and even the intended furnishings, can all play a part in this process.
Every building presents a unique challenge, and there is no standard strategy that is guaranteed to provide a perfect acoustic environment. Each case demands a bespoke solution, and that makes it important to engage the services of an acoustic engineer for your project. They will be able to create an acoustic model of the intended space, provide reliable guidance and help ensure that your acoustic solution complies with all the current legislation. Their advice can also help avoid the subsequent need for any costly retrofitting that might arise if an inappropriate acoustic solution is fitted initially.
Another key step that can help ensure a successful acoustic outcome is to involve a reputable acoustic ceiling systems manufacturer in the project design as early as possible. They will be able to work with you and provide acoustic performance data for your project, and this will allow the acoustic engineer to model the varying frequencies and acoustic behaviours involved. The manufacturer will then be able to advise on the requirements for each individual space and guide you through the different acoustic ceiling systems available on today’s market, helping to identify an appropriate solution that will meet both your practical and aesthetic requirements.
The manufacturer should also be able to offer support on site and advise on how their system can accommodate any features such as light fittings, bulkheads and access panels that may be present. Their recommendations on such things as substrate preparation and final finishing can often prove to be invaluable, and manufacturers will have trained and authorised installers who will provide the highest quality of installation.
While reliable and effective acoustic performance is a key requirement, aesthetic considerations also have a vital role to play, and the two elements should be made to work together. Traditional acoustic ceiling systems frequently use either a metal grid infilled with acoustic boards or boards that are perforated with multiple holes and used in conjunction with layers of mineral wool. While these methods may deliver some acoustic attenuation, they also restrict the design potential of the room involved, and over time they can easily become stained and unsightly.
Fortunately, modern alternatives are available which allow the creation of monolithic, seamless surfaces that combine the ability to satisfy the modern trend for clean, uncluttered lines with outstanding acoustic performance. This underlines the fact that today’s modern acoustic ceiling and wall systems can provide excellent performance while taking the bold visions that architects and their clients have for their buildings and translating them into reality.
Given the specialist nature of acoustic considerations, it’s not surprising that the subject is sometimes thought of as some sort of ‘secret’ known only to a chosen few. Yet, with careful consideration, and the help and guidance provided by specialist engineers and manufacturers, there is no reason why your next project shouldn’t sound every bit as pleasing as it looks.