Why Open Offices Fail Acoustically — and What Actually Fixes It

The complaint is always the same: "it's too noisy." But the measurement rarely is. Decibel meters in open offices usually read moderate levels. The problem is not volume — it is speech intelligibility.

The Real Problem: You Can Hear Every Word

In an open plan, you can hear the person three desks away but you cannot quite make out what they are saying. Your brain keeps trying. That is irrelevant speech — and it is one of the most reliable predictors of cognitive distraction in workplace research.

Reverberation is what causes it. Hard ceilings, glass, concrete and bare walls reflect sound, so every voice arrives at your ears several times over, smeared across hundreds of milliseconds. Even a quiet office becomes tiring when it is that reflective.

What Absorption Actually Does

Absorbent surfaces convert sound energy into heat rather than reflecting it. Practically, that:

• Cuts the reverberation time, so speech stops washing over the room
• Reduces the distance at which a conversation is intelligible — the reason a treated office feels private without walls
• Lowers the effort your brain spends filtering noise

Three Surfaces, Three Jobs

Ceiling — the biggest single surface, and the biggest win. Suspended PET baffles and clouds drop into exposed soffit ceilings and can be added without touching the services above.

Walls — fluted and flat PET panels treat the largest continuous reflective plane, and act as the design feature at the same time.

Between teams — laser-cut PET screens and partitions break sight lines and absorb at head height, which is exactly where speech energy lives.

Treating only one of the three gives partial results. In most open plans the ceiling comes first, walls second, screens third.

Specifying It

Two numbers matter:

• NRC (Noise Reduction Coefficient) — how much sound the panel absorbs, 0 to 1. PET felt runs 0.60 to 1.0 depending on thickness.
• Mounting — this is the one people miss. A 12 mm panel direct on the wall performs very differently from the same panel on 25 mm battens, because trapped air extends low-frequency absorption. If the spec only names the panel and not the mount, the performance claim is incomplete.

For commercial fit-outs, confirm reaction-to-fire classification pending documentation fire performance and recycled content up front — both are increasingly required in tender documents.

The Sustainability Angle

Recycled PET felt is made from post-consumer plastic bottles and is itself recyclable where facilities accept it. It is low-VOC and made without added formaldehyde, which matters in sealed buildings where air quality is already a concern.

You get the acoustic performance and a material story that holds up in an ESG report. That is a rare combination in a fit-out budget.