Transparent acoustic barriers

What is a transparent acoustic barrier?

A transparent acoustic barrier is a clear, dense material that blocks sound while letting people see through it and letting light pass. It does the same basic job as any acoustic barrier, stopping sound passing through, but without creating a solid wall.

There are two main types:

• Clear acoustic curtains: flexible, heavy, see-through sheet (often mass-loaded vinyl), supplied on a roll or cut to size with eyelets. They hang from fencing, scaffold or a frame, so they can move with the work.
• Rigid clear panels: acrylic or polycarbonate sheets in a frame. Clearer and tougher, but heavier, and usually used for longer-term or permanent installations.

When does see-through make sense?

Commonly used for:

• Safety sightlines: next to footpaths, junctions and site entrances, so drivers, plant operators and pedestrians can see each other
• Shops and businesses next to works, which need to stay visible to customers
• Neighbours’ daylight: where a solid barrier would shade windows or gardens
• Supervision: work areas a supervisor or banksman needs to watch
• Inside buildings: see-through dividers that split noisy machinery from quieter areas in factories and workshops
• Public-facing sites: where a solid wall would feel hostile or attract graffiti

What are the limits?

The main trade-off is absorption. Clear materials have hard, smooth faces, so they reflect sound rather than soak it up. A solid barrier with an absorbent face stops noise bouncing around the site; a clear one doesn’t. On a tight site, or where there are buildings on both sides, that reflected sound can matter.

The usual answer is to mix the two: clear panels or windows where people need to see, and absorbent panels everywhere else. Some systems are designed to combine clear and absorbent sections in one wall.

The other limits are the same as for any barrier:

• It has to block the direct path between the noise and the listener; being see-through doesn’t change that
• No gaps at joints or the base
• Height: fence-mounted curtains are limited to fence height, about 2 m
• Scratches and dirt reduce clarity over time; rigid panels need cleaning and can be damaged

Pros and cons

Pros

• Keeps sightlines for safety and supervision
• Lets daylight through to neighbours and work areas
• Keeps shops and businesses visible
• Feels less closed-in for the public

Cons

• Reflects sound instead of absorbing it
• Clear curtains are heavy for their size, and rigid panels more so
• Clarity can drop with scratches, dirt and weather
• Usually a lower Rw than the heaviest solid barriers, so check the data

What to ask for

1. What is the material’s tested Rw, from which lab and to which standard?
2. Is it a flexible curtain or a rigid panel, and how is it fixed?
3. Where are absorbent sections needed to stop reflections?
4. How are joints and the base sealed?
5. How does the material hold up to UV, weather and cleaning?

Hushtec’s transparent option

This site is supported by Hushtec, a New Zealand manufacturer of temporary acoustic barriers with a UK manufacturing site in Wakefield, West Yorkshire, where its Performance and Premium panels are made.

Hushtec’s transparent barrier is the Vision Series, a fully see-through panel made in 2.5 mm and 5 mm thicknesses for indoor and outdoor use, with Velcro joins so it connects to Hushtec’s solid panels. The 5 mm clear panel (5 kg/m²) is rated Rw 29 dB, close to Hushtec’s solid Premium barrier (Rw 32 dB). Hushtec’s headline figure for the Vision Series is “up to 42 dB” sound attenuation; as with any “up to” figure, the reduction you get on site will be lower and depends on layout.

Hushtec also builds Vision 5 panels into its pile and vibro hammer shrouds as viewing windows, and into the roofs of its acoustic tents, combining clear sections with absorbent Premium panels. To check whether a clear barrier suits your site, ask through the Get Help form.