There are many factors contributing to the quality of a sound environment. Especially in complex rooms like open offices, hospitals and learning environments. It is therefore important to have a clear understanding of how the different aspects of a design should be prioritised in relation to each other to ensure a high-quality outcome. Failing to do so increases the risk that untested presuppositions and biases will determine the quality of the given design, or in other words, that you put the cart before the horse.
We at Acoustic Bulletin recommend following what we call the Soundscape Design Pyramid as a methodological tool for prioritizing interventions when working with complex acoustic environments
The soundscape design pyramid
Unfortunately, compliance with regulatory requirements in many cases does not ensure a good sound environment. It is therefore always recommended that you take a holistic approach. It is necessary to consider all elements that affect the sound environment in a prioritised order. Acoustic design of rooms could be viewed as a pyramid, divided into four levels. The lower level of the pyramid is the most important and basic one. Each level above this becomes less important and more inefficient, if the below levels have not been addressed.
Our model for indoor soundscape design is shaped like a pyramid and, much like Maslow’s well-known hierarchy of needs, it deals with the most necessary and fundamental aspects at its base level. If the needs of the first level of the soundscape design pyramid are not met, tending to the needs of the second level will be ineffective, and will certainly not realise its full potential. If the needs of the second level are not met, tending to the needs of the third will not be impactful. And tending to the third level without having met the needs of the two previous levels would be a complete waste of time and effort.
1: Materials and geometry
This is the most important and fundamental level within acoustic design of rooms. First of all, one should consider which acoustic materials should be used in the room. Here, it is important to keep in mind that not all acoustic materials are of the same quality. Please see page 35 for more about acoustic absorption area on.
When considering how room geometry affects sound reflections within acoustic design, you could for the sake of overview, imagine sound waves as vectors. I.e. that the angle of incidence is equal to the angle of reflection, as illustrated in the diagrams on this page. You can easily see how you with this knowledge can angle surfaces or place absorbers strategically to reduce wall-to-wall reflections or noise pollution. OPS: This is an operational simplification. Sound is waves, and wave dynamics are far more complex than basic vector dynamics.
2: Interior: Plan design, functionality and furniture
It is then important to design the room in a functional manner, from an acoustic perspective. Noise sources should, to the extent that is possible, be screened from noise-sensitive activities. In relation to plan design, space application should be positioned going from quiet to noisier activities. Acoustic furniture and materials can be used for creating areas with a more effective acoustic private sphere.
3: People: Culture, psychology and policy
When the room and the decor have been acoustically optimised, you can also consider the human perspective. Behaviour may have a great effect on the noise level in a room, and a change in the sound culture could be required in many contexts.
4: Sound: Sources, products, amplification
If the three previous levels are fully optimised, or you wish to have a unique and different sound environment, you could consider adding technological and sound-related elements. Including sound installations, soundscaping and signalling.
OBS: It is important to underline that The Soundscape Design Pyramid describes different aspects of the sound environment that can be improved to benefit the users of the space. Even though the third level of the pyramid includes aspects related to the culture and psychology of the occupant’s of the room, this level only represents another design aspect of the sound environment that can be deployed to shape the sound environment. That is to say, the goal of acoustic design is of course to enhance the wellbeing and effectiveness of the end-users, but that the behaviour, psychology and culture of the users themselves should be considered to ensure good acoustic conditions for their own benefit.