How to Create a Good Acoustic Environment | DAMPA

DAMPA® is a Danish company specialised in the development and production of acoustic steel and aluminium ceilings, as well as acoustic wall panels for the building industry, with sales exclusively in the European market.

Acoustics has a great impact on everyday lives. But how do you create suitable acoustics? And can you create a room with too much acoustics and thereby the risk of creating a bad acoustic environment?

Acoustics are an important factor in everyday life. We cannot see the acoustics, and usually, we don’t think about it during the day – unless the acoustics are not right. Then we notice it right away, or it sneaks up on us in the form of e.g., headaches. Acoustics has a huge impact, regardless of whether it is in the workplace, in the classroom, or in the private living room. We are less effective, the ability to focus decreases, and the surplus of mental resources disappears.

• We have different acoustic needs depending on which room we are in
• The reverberation time is an expression of how quickly the sound falls by 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 acoustic 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

What are good acoustics?

Acoustics are an important factor in our everyday life, even when we do not notice them. Let us take a closer look at what acoustics are, their importance, and how we can create suitable and good acoustics.

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, the acoustics must be suitable for the room’s function and use. There is a big difference in the experienced acoustic reality depending on whether you stand in a classroom or a living room.

How to Create a Good Acoustic Environment for a Specific Room?

Users must consider several factors when creating suitable acoustics for the specific room. Depending on the room, DAMPA® has different needs for the acoustics. There is a big difference between the needs in a classroom versus an open-plan office.

In the classroom, we need the sound to travel, so that both the students in the front and the back can hear what the teacher is saying. The opposite is needed in the open-plan office, where we want to avoid the sound traveling too much.

The Different Absorbents

To create a good and customized acoustic environment, we need to add sound absorbers to the room so DAMPA® can reach the optimal reverberation time. Sound-absorbing elements can be many things: carpet, acoustic wall panels, acoustic ceilings, or other elements, which help to stop the sound.

Typically, one can differentiate between three sound absorbers:

• Porous absorbent
• Membrane absorbent
• Resonance absorbent

Depending on the sound-absorbing element, each element can absorb the sound, which is denoted by the absorption coefficient and is indicated by Alpha (a). To start with, we want the sound-absorbing elements to have an Alpha value as close to 1 as possible, as this means that all sound sent towards the element will be absorbed.

The Alpha value also determines which acoustic class the sound-absorbing element is a part of. The absorption classes are designated A-E, where absorption class A has the highest sound absorption.

What are good acoustics?

Acoustics are an important factor in everyday life, even when we do not notice them. Let us take a closer look at what acoustics are, their importance, and how DAMPA® can create suitable and good acoustics.

The Sound

Acoustics is an expression of how sound moves and reflects in a room. Sound consists of pressure waves that move across the air. Good acoustics are characterized by how quickly the pressure waves abeyance. The pressure waves are calmed with the help of sound-absorbing materials. When there is a room consisting only of hard surfaces, as brick walls and a concrete floor, the sound waves 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 talking with a person 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 enough absorbing materials are in the room to create optimal acoustics, users will get good speech comprehension.

Sound Absorbing Materials

To regulate and lower the reverberation time, we need elements that 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 elements with a low alpha value can be ideal, to ensure that the reverberation time does not become too low.

Examples of Sound Absorbing Materials

Sound-absorbing materials can be incorporated into a room in various ways. DAMPA® users can use both vertical and horizontal surfaces to create suitable and optimal acoustics.

• 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.
• Acoustic Wall Panels: In many cases, an acoustic ceiling is ideal, but when there is 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, as 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.
• Interior Design: Curtains, carpets, and upholstered furniture, along with other interior items, can also help reduce the reverberation time. However, this will rarely be enough to achieve optimal acoustics, but it will supplement walls and ceilings.

Finally, Get Knowledgeable Advice: When a user needs to improve the acoustics in a room, there are many parameters to consider. It is therefore important that users get expert advice from professionals to ensure that the solution the user chooses will solve the room's acoustic needs, so you do not end up with the wrong placement or too many sound-absorbing elements.