How to Tell How Soundproof a Room or Wall Is

tell how soundproof

Last updated: January 11, 2023 at 10:12 am

Noise disturbing the peace of your home can be a nightmare. That’s why this site exists, to give you all the tips and tricks you’ll need to soundproof your home and make it your haven again.

Once you’ve followed the advice and potentially spent a decent amount of money, how can you be sure that it’s worked? Especially if you are wary of neighbours still being able to hear you.

Types Of Sound

The first thing to remember is that there are several different types of sound. The key to reducing the noise you hear is to ensure that you are using the right materials.

Airborne sound is a high-frequency sound. It travels through the air and so is generally easier to block. Airborne sound includes talking, dogs barking, noise from the tv, appliances running, etc.

Impact sound is the noise created when walking, slamming the door, or moving furniture, for example. Your feet strike the floor and send vibrations through the floorboards, joists and into other rooms. This impact causes a low frequency sound which can be harder to block as the sound wave has more power.

So, you should ideally take this difference into account before you begin your project. If you’ve noticed your soundproofing is not as effective as you’d like, the wrong type of soundproofing may be the cause.

How Is Soundproofing Measured?

The rating for soundproofing is the sound transmission class (STC). It is based on the number of decibels blocked by the soundproofing material. STC ratings range from 25 to 65+. Here are a few examples:

  • A single-glazed window has an STC rating of around 25. You would be able to hear a person speaking at a normal volume clearly
  • A double-glazed window has a rating between 33-35. You could only hear someone clearly if they have raised their voice
  • A new 10-inch-thick brick wall would score 50. You wouldn’t hear voices and would only hear music if it was deafening on the other side
  • A commercially soundproofed property would rate at 65+, for example a recording studio

Signs of Soundproofing

If you’ve moved into a house and have either been told a room is soundproof or you suspect it might be, there are telltale signs you can look for.

  • Firstly, check the windows. They should be double-glazed and in good condition for soundproofing to be effective
  • Next, can you see a good layer of sealant around the windows and doors?
  • Do the doors have weatherstrips underneath them or between the door and the frame?
  • Look at the dimensions of the room. Does it seem a little smaller than it should be? This could be a sign of thicker walls
  • Are there blankets on the walls?
  • Does the room feel slightly eerie? This may seem an odd question, but people who have been alone in heavily soundproofed rooms report feeling strange due to the lack of background noise

4 Ways to Test Soundproofing

If you know your room or wall is soundproof, there are some ways to measure it. It may be slightly more difficult if the wall in question separates your home from next door, but there are still things you can do.

1. Listen for the Noise That Was Bothering You

Presumably, you installed soundproofing because there was a particular noise that was bothering you. To see if it’s still a problem, go into the room and see if you can still hear it.

If it’s gone, or substantially lower, problem solved. If you just suspect it might be soundproofed, walk between two rooms, and see if you can notice a difference.

2. Check Background Noise

The first simple step is to download a decibel checker on your phone. There are plenty of free ones on the app stores. To check the effect of the soundproofing, first go into the next room, stand quietly and start to measure the background noise level. It should be no more than 60 dB if you live in the city and 45 dB in a suburban area.

Make a note of the maximum decibels and then return to the soundproofed room. Now measure the background noise here. If the room has been soundproofed well, it should be lower.

3. Play Something Loud

Either have someone switch on something loud in the first room or do it yourself and then return to the soundproofed room.

Close the door and record the noise levels again. If the room is well soundproofed, you should notice only a minor difference in the noise levels compared to the first test. If the noise levels rise significantly then the soundproofing is either absent or ineffective.

4. Hire a Professional

If you want a more recipe measurement, you can hire a company to test for you. These companies are normally used in new builds to confirm the soundproofing levels are up to code.

They can use professional equipment to test the exact amount of noise reduction your soundproofing provides. 30 dB is the difference between talking normally and a whisper so if your soundproofing reduced the noise this much it is working well.

The only reason you should need this level of accuracy though is if you’re engage in a noise dispute or if you’re want to use the soundproofing as a benefit to raise the price when selling your home. This might be particularly desirable if you’re selling a flat in a busy city centre, for example.

Can a Room Be Completely Soundproof?

Yes, it is possible to complete soundproof a room. If you use acoustic tiles, designed for recording studios, coupled with double-glazing and sealant round the windows and door you can reduce the decibel level to zero. However, it’s not recommended that you go this far for several reasons.

  1. Firstly, acoustic tiles are very expensive. It is money that you don’t need to spend, as moderate soundproofing will restore peace to your home.
  2. Secondly, as explained above, many people find a complete lack of background noise unsettling.

It’s best to leave it so you can hear a low hum. You don’t want to spend a fortune and then find it so disturbing you must take it all down again.

Finally, you do need to be able to hear sounds from the outside world, whether it’s one of your children calling you from another room or just the sound of the doorbell.


The easiest way to test soundproofing is to download a free decibel app to your phone. Measure the background noise in the soundproofed room and then play a loud noise in the next room.

If the background level remains the same, the room is soundproof.

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About the Author: Claire

Hailing from the North-East, Claire has been writing for Quiet Living since 2020 and has built a wealth of knowledge in home improvement, with a keen interest in knowledge based articles.

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