It is a common hope that a blind will quieten a noisy road or a loud neighbour. The honest answer is that blinds help a little, not a lot - but some help more than others, and the right combination makes a real difference. Here is what works.
The honest answer first
Most noise comes through the glass, not the gap a blind covers, so a thin blind does very little for sound. What does help is mass and trapped air: a dense covering, and a layer of still air between it and the window, absorb and slow sound rather than letting it bounce around the room. So the question is which blinds add mass and an air gap.
What helps most
- Honeycomb (cellular) blinds are the best single choice. The air pockets that make them insulate also dampen sound, and a close fit adds a trapped-air layer at the glass.
- A thick, lined Roman blind adds real fabric mass and softens echo, more than a thin roller can.
- Layering - a blind plus heavy curtains - stacks mass and air gaps and does more than either alone.
What does little
A single thin roller, and any slatted or louvred blind (venetian, vertical), do least for noise, because they are light and the slat gaps let sound straight through. They are fine choices for other reasons, just not for quiet.
The bigger picture
If noise is a serious problem, the glazing is where the real gain is - secondary glazing or a better-sealed window will outperform any blind. Treat a blind as a soft, affordable add-on that takes the edge off: a honeycomb blind, fitted snugly and ideally paired with curtains, is the most a window covering will sensibly do for sound.