This article aimed at laying the groundwork for a foundation of knowledge in acoustics in buildings. Let's get started!
Why Acoustics in Buildings Matters?
At its most fundamental, sound is a very small and very quick variation in air pressure above and below atmospheric pressure. Our ears do not perceive sound in a linear manner. Instead, it adopts a logarithmic scale and measures energy in decibels (dB). To the ear, a sound heard at 60dB only needs to be reduced to 50dB to be perceived as half as loud.
Furthermore, a change in volume from 60 dB to 40dB (for example, from a busy street to a quiet library) would be interpreted as a more dramatic change.
Since humans spend 90% of our lives indoor, surrounding sound should be at a comfortable level to boost well-being. Statistics has shown that our well-being is sensitive and being exposed to excessive noise can lead to high levels of stress, headaches, and negatively influence our sleep.
Unfortunately, the current design trends that are promoting the construction of open workspaces for collaboration may have the unintended consequence of reducing privacy and productivity. Furthermore, some of the construction approaches and items chosen to satisfy sustainability goals may accidentally undermine a space's potential to provide occupant comfort by reducing unwanted noise.
How is Acoustic Performance Measured in Architecture?
Acoustical engineers use decibels to estimate sound loudness, but when it comes to architectural acoustics, we use acoustic absorption and sound transmission loss to evaluate the acoustic performance of a building.
Acoustical absorption is a material's ability to absorb rather than reflect sound (think about the difference between jumping into a pile of pillows vs onto a trampoline). Meanwhile, sound transmission loss refers to the ability to reduce sound transfer from one space to another (i.e. blocking noise or sound between rooms). When looking for a solution to meet good architectural acoustics criteria for your next project, it is critical to understand the distinction between the two.
In terms of sound absorption, you need to look for products that absorb reverberation and echoes in a room. However, to halt or block sound, you will need a thicker, denser material. Materials with strong sound absorption are ineffective at preventing sound transmission and vice versa. Concrete, for example, is excellent for sound transmission loss but not for sound absorption.
Rockfon’s stone wool ceiling tiles have a high absorption capacity, whilst ROCKWOOL's wall and roofing insulation materials, when used as part of an assembly, can help minimise noise between rooms as well as noise from the outside environment. The acoustical qualities of the building materials you specify and utilise will play a considerable influence in overall soundproofing depending on the application.
What is Architectural Acoustics?
Architectural acoustics is the study of sound in buildings, as well as the design of those structures for best acoustic performance, which includes sound transmission management, speech intelligibility, and sound isolation for speech privacy.
How Environmental Noise Affects Health and Well-Being?
Every sound we hear on a daily basis can lead to a variety of issues. Environmental noise, in particular, has piqued the interest of European academics, who have lately quantified the health risks it can provide. In addition to lowering the occupants' energy levels, these problems can range from heart disease and tinnitus to sleep deprivation and cognitive impairment. Furthermore, environmental noise can potentially shorten the typical person's life by years.
Transportation noise – such as road traffic, railways, and aircraft – as well as wind turbine noise and recreational noise – are all examples of environmental noise. Leisure noise encompasses all noise sources that people are exposed to at locations such as nightclubs, restaurants, fitness classes, live sporting events, and live music venues. In such settings, the potential for the bothersome vocal phenomenon known as the "Lombard Effect" is high.
‘Acoustics affects our well-being and the environment around us. Bad acoustics can ruin your conversation in a restaurant. Would you go back to a restaurant where you couldn’t hear your companion properly – too noisy, right? When the acoustics of a space is sound, it influences the overall ambience of the space. Today, even neuroscientists talk about the importance of acoustics and its increasing relevance,’ stressed Jasper Spigt, architect and partner at architecten Van Mourik
Architectural acoustics, on the other hand, have a vital impact in the occupant's experience even within the bounds of a building. In fact, environmental noise might be intermittent and decrease during the evening and overnight hours, however excessive reverberation inside a room is continuously there, interfering with every word spoken.
How Building’s Construction Contributes to its Architectural Acoustics?
Each component of a building's construction contributes to its architectural acoustics. It is more than simply the walls and ceilings: the shapes, surfaces, furniture, light fixtures, mechanical systems, and materials used in construction all have an impact on the acoustics of a building. When the acoustical qualities of materials are not taken into account throughout the design process, the end result is too often a bad acoustical environment. The discussion about healthier buildings frequently centres on light and air quality, but noise levels can have a substantial impact on health and welfare.
According to studies, young pupils performed 5.5 points poorer on their national standardised test for every 10dB increase in noise pollution. In order to support appropriate teaching and learning environments, the WHO recommends a noise level in classrooms of less than 35dB(A).
Acoustic ceiling tiles or wall panels can help improve sound quality and have been demonstrated to lower ambient noise by up to 50%. They can reduce background noise or eliminate echo entirely, resulting in a happier, more inclusive environment.
What is the Risks of Poor Architectural Acoustics?
The possible issues from improper acoustical design might vary substantially depending on the type of construction. Let's take a look at the various negative impacts that noise can have in different architectural environments.
How Poor Architectural Acoustics Affect Patients and Caretakers in Healthcare Building?
- Startle reflexes can be triggered by loud noises, resulting in damage, increased blood pressure, and accelerated respiration rates.
- Prolonged noise exposure can lead to memory issues, discomfort, decreased pain tolerance, and feelings of isolation.
- Noise reduction in intensive care units has been shown to promote greater sleep and healing.
- Healthcare personnel frequently execute vital jobs in high-stress settings, including high levels of noise, which contribute to exhaustion.
- When noise is unmanaged, speech privacy and intelligibility are very serious issues in healthcare contexts. Doctors and nurses must be able to spot and respond to auditory cues quickly and precisely while protecting patient confidentiality.
How Poor Architectural Acoustics Affect Employees in Office Spaces?
When not adequately handled, acoustical design in an office setting can significantly impede productivity and inhibit privacy. For quite some time, open design concepts in the workplace have been on the rise, in part because they promote more cooperation and collaboration among colleagues, reduce response times to requests, and improve vital communication.
However, because there are fewer surfaces to absorb noise from talks, meetings, mechanical systems, and other background sounds, these types of settings may result in louder working conditions and frequent distractions.
The transition to open-concept offices incorporates glass walls, high ceilings, and low partitions to allow for more natural light and warmth. However, it can also contribute to increased distraction and reduced productivity. In these designs, privacy may be non-existent.
Nevertheless, typical floor plans with closed-door offices and classrooms frequently lack an effective acoustical design and thus create a misleading appearance of privacy. Short-term health issues associated with poor acoustics include increased stress, anxiety, elevated heart and breathing rates, and muscle tension.
How will Architectural Acoustics be in the Near Future?
For the World Health Organization, noise pollution is number two on the list, while air pollution is number one. In the coming years, we have to be more aware of the effect of noise in all kinds of spaces and the growing importance of acoustics in building design.
Nowadays, noise is not defined as ‘unwanted sound’ but ‘unwanted sound without getting any hearing damage’. This helps us point out that noise is unhealthy and can be disturbing at various levels.
Today, even universities are discussing the harmful effects of noise and best practices to integrate acoustic building design. That’s why, more than ever, we need architectural design and building construction that consider these aspects. After all, we all want to contribute towards a healthy sound environment.