Acoustics are important in everyday life, even when we do not notice them.
Let us have a closer look at what acoustics are, their importance, and how we can create suitable acoustics.
GOOD ACOUSTICS EQUALS ACCUSTOMED ACOUSTICS
Acoustics are an important factor in our everyday life, even when we do not notice. Are the acoustics bad in e.g., the workplace, we get less effective, we cannot concentrate and in the meeting room, we miss out on the important details. We have different needs for acoustics depending on what function the room has. Therefore, it is important, that the acoustics are suitable to the room’s function and use. There is a big difference in the experienced acoustic reality depending on whether you stand in a restaurant or at the children’s playground.
THE SOUND
Acoustics is an expression for, how sound moves and reflects in a room. Sound consists of pressure waves which move across the air. Good acoustics are characterized by how quickly the pressure waves abeyance. The help of sound-absorbing materials calms the pressure waves. When we have a room only consisting of hard surfaces the soundwaves will be thrown around in the room for a long time before settling. When that happens, we talk about a long reverberation time, also known as echo.
REVERBERATION TIME
Theoretically speaking, when we talk about good or bad acoustics, we look at the reverberation time. The reverberation time is decided by how many seconds it takes for the sound to fall with 60 dB after the sound source has stopped. For example, if you are two people talking in a room with a long reverberation time, the first spoken words will not die out before the next words come. It will therefore be hard to have a conversation. However, if there are enough absorbing materials in the room to create optimal acoustics, we will get good speech comprehension.
SOUND ABSORBING MATERIALS
To regulate and lower the reverberation time we need elements, which can absorb sound so that it does not reflect in the room. The ability of elements to absorb sound is denoted by the absorption coefficient and is indicated by Alpha (a). As a starting point, it is desired that the sound-absorbing elements have an Alpha value as close to 1 as possible since the value 1 means that all sound sent towards the element is absorbed. The closer to 1 the alpha value for a sound-absorbing element is, the fewer elements are needed in the room. It is important to create synergy between the function of the room and the sound-absorbing elements. For example, acoustic ceilings cover a large area, which is why many acoustics elements with a low alpha value can be ideal, to ensure that the reverberation time does not become too low.
EXAMPLES ON SOUND ABSORBING MATERIALS
Sound-absorbing materials can be thought into a room in various ways. You can use the vertical and horizontal surfaces to create suitable and optimal acoustic.
ACOUSTIC CEILINGS
The ceiling is often ideal to use as a sound-absorbing element, as there is a large disposable surface, where sound-absorbing materials can be added. At DAMPA we combine perforation ,acoustic felt and insulation, which together will absorb noise and add to a good environment.
Our wide range of acoustic ceiling solutions is ideal for rooms intended for high levels of human noise such as corridors, cabins and public areas. A good environment enhances the passengers and crew to concentrate and relax.
Read more about DAMPA’s acoustic metal ceilings here.
ACOUSTIC PANELS ON THE WALL
In many cases an acoustic ceiling is ideal, but when we have a room with a high ceiling, the sound-absorbing material will be far from the sound source. In those cases, it is more efficient to add sound-absorbing materials to the walls, while these will be closest. As a rule of thumb, the walls should be covered with absorbing materials equivalent to approximately 10-20 % of the floor area. For example, if you have a floor area of 100 m2 you need 10-20 m2 absorbing materials on the walls to secure optimal acoustics. Furthermore, the acoustic panels are a quick, easy, and accessible way to optimize the acoustics in any room.
Read more about DAMPA’s acoustic panels, Silent Board, here.
INTERIOR DESIGN
Curtains, carpets, and upholstered furniture along with other interiors can also help reduce the reverberation time. However, this will rarely be enough to achieve optimal acoustics but will act as a supplement to walls and ceilings.
GET KNOWLEDGEABLE ADVICE
When you need to improve the acoustics in a room, there are many parameters to take into consideration. It is therefore important that you get expert advice from professionals to ensure, that the solution you choose, will solve your acoustic needs, so you do not end up with the wrong placement or too many sound-absorbing elements. Furthermore, it is important to ensure that the selected sound-absorbing materials work as intended. Choose thoroughly tested elements with the right documentation. You are always welcome to contact us by email at dampa@dampa.dk or telephone at +45 63 76 13 00 for a non-binding talk about solutions for your acoustic needs.
TAKEAWAYS FROM THE ARTICLE
- We have different acoustic needs depending on which room we are in
- The reverberation time is an expression of, how quickly the sound falls with 60 dB
- To lower the reverberation time, we need to have acoustic elements in the room. Their ability to absorb sound is denoted by the absorption coefficient (alpha). The closer the alpha is to 1, the better the element is at absorbing the sound.
- Examples of sound-absorbing materials are acoustics ceilings, acoustic wall panels and interior elements such as curtains, carpets and upholstered furniture.
- The rule of thumb says that if you use acoustic wall panels, the walls must be covered corresponding to 20% of the floor area