How to Expertly Block Out Low Frequency Noise

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Last updated: July 26, 2021 at 9:35 am

We’ve covered many different types of noise on this site and how to minimise or even block them altogether. A kind of noise we haven’t covered is low-frequency. It’s an important topic as this type of sound can be the hardest to block and the most intrusive.

Many people can’t even hear it, but those who describe a low rumbling or humming sound. It can cause a substantial amount of distress for those able to hear it – sufferers have reported feeling anxious, trouble sleeping, and even high blood pressure.

What Is A Low Frequency Noise?

Low frequency sounds register in the range of 10Hz to 100Hz. It’s a type of noise that’s almost felt rather than heard, which may explain why a persistent low-frequency noise problem can be so unpleasant.

Common causes:

Neighbour playing electric guitar through an amp, generators, boilers, fans, pumps, motors or nearby construction work.

Before starting any soundproofing, it’s important to find the source of the noise to establish how to do it properly.

  • Check walls and floor if noise is travelling through them
  • Check appliances, especially fridge freezers, for any humming

5 Ways to Block Low Frequency Noise

As explained above, blocking low-frequency sound can be more complicated than blocking other types of sounds. Low-frequency sounds have a longer sound wave meaning they’re more powerful and travel further. There are some solutions you can use, however.

1. Install Bass Traps

As the name suggests, bass traps absorb low-frequency sounds. They’re made from a type of acoustic foam and are easy to install if your DIY skills aren’t great. You simply install them in each corner of the room(s) you want to protect from the noise that’s bothering you. They aren’t particularly expensive either, so this could be a good first step for you to try.

2. Use Soundproof Curtains or Blinds

When soundproofing a room, a critical weakness is the windows. Even when they’re double-glazed due to gaps in the frames and round the edges, sound can still get through. It’s likely a large amount of the nuisance noise you’re hearing is entering this way. Soundproof curtains are made of thick material which blocks and absorbs sound. You should notice a significant improvement once the curtains are in place.

If you’re particularly handy with a sewing machine, you could even make these yourself. Look for soundproof curtains online and see what materials manufacturers use. You can then buy some and use it to line your favourite curtains.

As well as curtains, you can also buy soundproof blinds. They are either made of extra-thick sound absorbent material, or they’re made in a honeycomb design. Both are designed to trap sound and prevent it from getting through. If you pair these with soundproof curtains, it will make a huge difference.

3. Completely Soundproof The Room

If you’re bothered by the noise in one room, then completely soundproofing it is an option. There are various ways you can do it; for more advice, check out the other articles on this site. Here are the basics, though.

  • Install acoustic plasterboard over your existing walls. It’s thicker and made of sound-absorbing materials, so it should block a lot of the noise.
  • Apply Green Glue compound to your existing wall and then put another layer of drywall over it. This compound traps sound and converts it to heat, so when you add this to the extra mass from the additional plasterboard, almost all sound should be blocked.
  • Use Mass Loaded Vinyl between your existing wall and a new layer of plasterboard. MLV is very thin and easy to install. It blocks and absorbs sound, so it should reduce the noise you can hear to almost nothing.
  • Fit Acoustic Tiles. They are expensive, but they are almost guaranteed to block all sound as they’re used in recording studios. They are expensive, so it would only be advisable if you have a huge noise problem. Plus, if you soundproof a room to this extent, you may find the complete lack of sound unnerving.
  • Use soundproof strips around gaps in the door and/or hang a heavier door.
  • If you have wood floors, it’s likely the sound is vibrating through it. Consider laying a thick carpet or rugs to add extra soundproof mass.

Please remember:

With any of these solutions, the devil is in the detail. You need to seal up your walls entirely. It’s a good idea to lay the plasterboard in a staggered fashion so they cover up the existing wall joins. Once the second wall is hung, seal the joins with acoustic tape and use acoustic sealant around the edges, light switches and power sockets.

4. Hang Soundproof Blankets On The Wall

This is a good solution if the noise that’s bothering you is likely to be temporary. Simply hang the blankets up in the room you’re trying to soundproof. Most come with fittings to hang them on the walls, so it isn’t a difficult task. You could even move them from room to room if you wanted. In the living room through the day and then hang them in the bedroom before you go to sleep.

They come in a range of designs and patterns so they could look like a design feature in your room rather than being purely utilitarian. Make sure the kind you get is fully quilted to ensure they block the low-frequency sounds that are bothering you. Non-quilted ones will have a partial effect, but they’re made to stop higher frequency sound, so they won’t work as well.

5. Isolate the Culprit

This technique is often used outside for pool pumps and generators, and works best for smaller appliances. This involves encasing the culprit in a soundproof box lined with acoustic foam (or other similar soundproof material) to stop low frequency noise at source.

Conclusion

Any type of regular, unwanted noise can be stressful and spoil your enjoyment of your home. Low-frequency sound can have a detrimental effect on your stress levels and health. Because of its long wavelength, low-frequency sounds can be more difficult to block, and you may need to experiment based on your budget and the level of noise you’re experiencing.

Soundproofing is the most guaranteed method, but if the noise is likely to be temporary or only just audible, then rugs, curtains, and blankets may be enough. Hopefully, these options will allow you to find the right solution and restore peace in your home again.

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About the Author: AJ

Hi, my name's AJ! I write about living a quieter life, soundproofing tips and recommending the best quiet products here on Quiet Living.