Making a room quieter

Noise complaints cover two entirely different problems, and confusing them is why so many attempted solutions fail.

The two problems

Sound entering from elsewhere — neighbours, traffic, other rooms.

This requires blocking sound transmission, which needs mass, sealing and separation.

Sound within the room — echo, reverberation, a room that sounds harsh and in which conversation is effortful.

This requires absorption, which needs soft materials.

Soft furnishings improve the second and do very little for the first, which is why adding rugs and curtains disappoints people trying to block a neighbour.

Reducing sound within a room

The easier problem.

Hard parallel surfaces reflect sound, which is why an empty room with bare floors and walls sounds harsh.

The solutions are soft, and the more surface area covered the better.

Rugs and carpet, which are the most effective single change for a hard floor.

Curtains, particularly heavy ones, and particularly covering more wall than just the window.

Upholstered furniture rather than hard.

Bookshelves with books, which are genuinely effective acoustically because of the irregular surface.

Wall hangings and acoustic panels.

Plants, which help modestly.

The improvement is generally noticeable within a room, and it addresses the harshness rather than the neighbour.

Reducing sound from outside

The harder problem, where the physics is unforgiving.

Sound transmission is reduced by mass, by sealing gaps, and by separating structures so vibration does not carry.

Sealing gaps is the cheapest and frequently the most effective.

Sound travels through small openings very effectively, and gaps around doors, under doors, around pipe penetrations, around windows and at floor junctions all transmit substantially.

Draught-proofing a door reduces noise as well as heat loss, and a solid door is far better than a hollow one.

Windows are frequently the weakest element for external noise.

Secondary glazing — a separate internal window with a substantial air gap — is considerably more effective for noise than replacing double glazing, since the gap matters more than the number of panes.

Mass on walls, which means adding layers, and which is a construction job rather than a decorating one.

Acoustic plasterboard on resilient bars is the standard approach, and it reduces room size and requires the wall to be redecorated.

Floors, where impact noise from above is transmitted through the structure and requires resilient layers to address.

Carpet and underlay in the room above is the single most effective measure for impact noise, which is why it is so frequently a source of dispute in flats.

What does not work

Worth stating, since these are widely sold.

Foam acoustic panels, which absorb within a room and do essentially nothing to block transmission, despite being marketed for both.

Egg boxes and similar, which do nothing.

Thin adhesive materials applied to a wall, which lack the mass required.

Anything that does not add mass, seal a gap or separate structures is not going to reduce transmission.

The other approaches

Where structural solutions are not available, as in most rented properties.

Rearranging the room so that beds and seating are away from the shared wall.

Placing bookcases or wardrobes against the shared wall, which adds some mass.

Masking sound — a fan, a white noise source, or music — which does not reduce the noise and does reduce how noticeable it is.

This is a genuine and evidence-supported approach for sleep specifically.

And earplugs, which are the most effective and least satisfying answer.

The neighbour question

Which is frequently the actual issue.

Most noise disputes are resolved by conversation rather than by construction, and the majority of people are unaware they are audible.

Raising it early, pleasantly and specifically works considerably better than accumulating resentment and then escalating.

Where it does not, local authorities in many jurisdictions have statutory nuisance powers, and keeping a dated log of incidents is what any formal process will require.

General information only, not professional advice. Consult a qualified professional for structural acoustic work, and your landlord or local authority regarding noise nuisance.