How to Block Sound Between Rooms

Updated April 27, 2023

Whether it’s a clamoring kitchen or a convivial conference room, most businesses have at least one especially loud area.

Ambient noise doesn’t care about the kind of atmosphere you’re trying to create, however, and sound can easily travel between spaces to annoy others. But if you know how to block sound between rooms, you can create a tranquil ambiance adjacent to the rowdiest of spaces.

Whether you’re sonically isolating areas of your own business or blocking out a noisy neighbor, this guide will outline how to work with your space’s doors, ventilation, and walls to prevent sound spillover.

How Does Sound Escape a Room?

To learn how to reduce noise between rooms, we must first understand a bit about the nature of noise. Sound travels as vibrating waves through the open air until it reaches a surface. Then, depending on the nature of what the sound wave comes into contact with, the sound is either:1

  • Reflected
  • Absorbed completely
  • Dampened

Thus, when a sound wave travels from one room to another, it generally occurs in two ways:

  • Through gaps such as those around doors and ventilation.
  • As vibrations through walls.

In order to minimize noise transfer through walls, you’ll want to ensure there are no gaps between rooms and drape sound absorbing materials from the floor to the ceiling. While this may not stop the noise transfer from one room to another entirely, it can help muffle the sound. This solution may already be familiar to many, as these are the types of techniques recording studios use to maintain premium sound.

For safety, utility, and monetary reasons, most businesses can’t outfit their space in the same style as a recording studio, however. So, how can they keep unwanted noise contained?

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Preventing Noise Transfer Between Rooms

Each business has unique needs regarding the type of space they’re working with and the kinds of sounds they’re dealing with. Hence, every space has its own acoustic issues that can be discerned and remedied by a noise reduction specialist. Regardless, there are a few common culprits (and equivalent solutions) to look for when trying to reduce noise transfer between rooms.

Deal with Drafty Doors

That cool breeze blowing through the gaps in your doorframe isn’t only driving your heating bills up—it’s a sign that excessive outside noise is getting in and out. Both the type of door and the snugness of its installation affect how much sound escapes through it (or finds its way in).

One way to assess acoustical materials is by their Sound Transmission Class (STC). The higher an object’s STC value, the greater its ability to block airborne noise. Without proper sealing, the STC values of two common door materials are:2

  • Wood – 22
  • Steel – 17

However, with heavy-duty acoustic seals completely enclosing a door in its frame, sound loss is reduced dramatically. Those same doors’ STC values shoot up significantly after proper sealing:2

  • Wood – 31
  • Steel – 35

Businesses (such as offices and restaurants) that have different noise zones can dramatically dampen the roar from other areas by properly sealing their doors. And, if maximum quietness is a concern, they can go even further and install a completely soundproof door.

But if drafty doors aren’t the reason for your loud workspace, perhaps something even airer is the problem.

Vanquish Ventilation Noise

Vents present a particularly potent problem for noise reduction, as they can’t simply be sealed off and forgotten about. They’re necessary to maintain the airflow and environment inside a building. Despite the inability to block them, there are a few techniques to reduce the amount of unwanted noise that sneaks through your vents, such as:3

  • Sealing the cracks between the vent and the wall – This is the easiest and most obvious place to start, as it doesn’t involve getting inside a building’s walls. A high-quality sealant such as GREENchoice Titebond Acoustical Sound Sealant caulked around the vent’s edges will dampen the sound’s ability to slip through the cracks.
  • Lining the ducts with a sound-absorbing material – The enclosed and acoustically reflective nature of ducts makes them a prime place for sound to reverberate endlessly. Sliding in a noise-reducing medium like Quiet Liner will inhibit noise’s ability to echo through them.
  • Wrapping vents – This technique takes a bit more foresight (or wall deconstruction) than the other two solutions, but its impact on noise levels is worth the effort. Wrapping vents is a salient way to increase their surface mass, effectively reducing the amount of sound they transfer.

Work on the Walls

There are about as many approaches to improving walls’ sound absorption capacities as there are buildings. Nevertheless, a few solutions involve applying mass to the finished surface by using products like Wood Wool, the Sound Silencer, or a Quilted Curtain. You may also consider creating a double layer of drywall with Green Glue. Another option we recommend is applying our Noise S.T.O.P.™ Vinyl Barrier product directly to the framing and then installing a layer of drywall. This is best for locations where space is an issue. The malleable structure of this product conforms to the surface you apply it to, and there are a variety of simple ways to secure it in place, including screws, staples, or hooks and grommets.

But if the raucous traveling through your space gets overwhelming and basic barriers aren’t enough, consulting an acoustical expert can help you more thoroughly cancel out intrusive noises.

Stop the Spread of Sound with Acoustical Surfaces

Every business has different soundproofing and sound absorption needs. For industrial spaces, the high-frequency whirring of machines may need to be dampened with vibration-absorbing pads or encapsulated with Soundproof Blankets such as Interior or Exterior Quilted Curtains or Echo Barrier Curtains.

For customer service-oriented operations, aesthetics may be of the utmost importance, and any acoustical materials must be as eye-pleasing as they are effective.

Whatever your business’s acoustical needs, Acoustical Surfaces offers an abundance of soundproofing materials to keep sound in (or out). Contact us to see how we can help your business achieve the purest silence possible.



  1. Boston University. Making the World a Lot Quieter.
  2. National Research Council Canada. Sound transmission through double doors.
  3. Acoustics. Acoustical Treatments on Ventilation Ducts through Walls: Experimental Results and Novel Models.

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