by INbtwn

Sound,
clearly explained.

Colourway
01

How sound works.

Sound is movement in the air.

In a room, that movement meets the walls, floor and ceiling. Hard surfaces reflect almost all of it. Soft, porous material turns some of it into a tiny amount of heat.

The more sound is reflected, the longer it lingers. Words overlap, everyone speaks louder to be understood, and the space becomes tiring.

Without absorption

Sound bounces from wall to wall. Each word mingles with the echo of the last.

With absorption

Some sound is absorbed at each reflection. Reverberation fades more quickly.

02

Three different things.

Often confused, but each calls for a different approach.

  • Absorption

    Less reverberation within the space itself.

    Soft, porous material on a wall or ceiling, or as a freestanding element.

  • Insulation

    Less sound reaching the space next door.

    Mass and airtightness in walls, doors and ceilings. Acoustic treatment on a wall alone will not do this.

  • Speech privacy

    Conversations that are harder for others nearby to follow.

    A combination of absorption, screening and distance between areas.

03

Four key terms.

Briefly explained, without the jargon.

  • RT60

    Reverberation time

    The time it takes for the sound level to fall by 60 dB after the source stops, measured in seconds.

    A classroom or meeting room usually needs a shorter reverberation time than a church, so conversations remain intelligible.

  • αw

    Sound absorption

    A value from 0 to 1 indicating how well a material absorbs sound.

    A higher value means more absorption with the tested mounting. A value of 1 does not mean every frequency is fully absorbed.

  • A – E

    Absorption class

    A sound absorption rating under EN ISO 11654. A is the highest class.

    The class applies to the tested construction: thickness, finish and the gap behind the material also affect the result.

  • Hz

    Frequency

    The number of vibrations per second. Low-pitched sounds have a low frequency; high-pitched sounds have a high one.

    A deep hum needs a different approach from voices. The thickness and gap behind the material help determine which frequencies it absorbs.

04

Measure first, then make.

So we know what the space needs before we design anything.

  1. 01

    Analysis

    Shape, volume, materials and how the space is used. Where needed, a specialist partner measures reverberation.

  2. 02

    Calculation

    How much absorption is needed, and where it has the greatest effect.

  3. 03

    Advice

    A proposal covering material, position and form. Sometimes less is enough.