How to make a soundproof wall? (A Comprehensive Guide)

This blog post will answer the question, “What are the methods to soundproof a wall?” The ways in which sound can transmit through walls, what are the key principles of soundproofing than others, and the benefits of soundproofing a wall.  

How to make a soundproof wall?

There are several key methods to soundproofing a wall

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  • Acoustic Caulk
  • Acoustic Curtains
  • Rearranging the furniture
  • Soundproof Wallpaper/Paint
  • Mass Loaded Vinyl
  • Additional Drywall
  • Acoustic Foam Panels
  • NoiseProofing Sealant

How can noise transmit through a wall?

Noise can transmit through a wall in two ways:

Airborne Noise: They are sometimes referred to as ambient noise are sounds transmitted through through the walls, floors & ceiling. This can include a general conversation between people, TVs, pets, musical instruments and so on and so forth. 

Thus, the sound vibrations through these sources travel through the interstitial spaces between the walls and can diffuse into the adjacent floor space causing disturbance or reducing privacy.

Impact Noise: This type of noise is generated when some object or person directly makes contact with the wooden floor boards, walls etc. There are several examples, feet stomping, falling objects, objects being dragged across the floor, musical instruments and so on.

Image 1: Ways in which sound can infiltrate a space

Benefits of Soundproofing a wall

Below are the benefits of soundproofing a wall:

  • Makes the room isolated from unwanted noise which can disturb activities such as studying or sleeping.
  • Reduction of ambient wind noise that can take place from airborne transmission.
  • Improves room comfort and a general level of cosiness.
  • Prevent sound leakage into adjacent spaces thereby improving privacy.

Sound Absorption Vs. Sound Blocking, which to consider?

Now, contrary to conventional usage of Sound Blocking Vs. Sound absorption which are often incorrectly used interchangeably, lets study below what they actually mean:

Sound Absorption happens when vibrations from a sound source are absorbed by acoustical absorbing surfaces or elements which reduce reverberation, echoing & amplification.

Materials used for this function are typically porous and plentiful air gaps to enhance effectiveness.

Sound Blocking or Sound Isolation seeks to contain the sounds emanation from a source within the boundaries of a predefined area.

Materials used for this function are typically dense, thick and heavy with as little porosity as possible.

Key principles of SoundProofing

The prevention of sound waves passing in or out of a room resulting in acoustic isolation of the designated space is known as soundproofing.

These are fundamental aspects of Sound Proofing:

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Deflection

Deflection of sound waves is achieved by adding dense non porous materials to any structure. This kind of material is very effective at deviating or deflecting noise made through airborne transmission. 

The additional bulk helps to dissipate soundwaves by creating a longer path and therefore higher energy requirement to diffuse into any given space.

However, blocking impact borne transmission is not as effective. It is a higher power, pressure and vibration class than airborne vibration.

Absorption 

Absorption is the phenomena by which sound pressure waves are distributed across a surface with interstitial airspace that prevents transmission through vibration of solid molecules.

Thereby soaking up acoustic energy. Materials such as this  are usually installed in open cavities where the depth of material can be tolerated.

In addition, this kind of material can also prevent additional resonance, reverberation and amplification of sound waves that could be created had the cavity been left empty.

There are 2 types of Absorbers:

Porous absorbers:

Porous open cell foams are highly effective noise absorbers across a broad range of medium-high frequencies. Performance can be less impressive at lower frequencies. The absorption profile is dependent on a number of factors such as:

  • Cell Size
  • Tortuosity
  • Porosity
  • Material Density 
  • Material Thickness

Resonant Absorbers:

Resonant absorbers also called Helmholtz Absorbers work by damping a sound wave while reflecting it. The absorption of a resonant soundwave works only over a low-medium frequency range

Reflection

The comparative distribution of sound pressure variations throughout a given space, or the process by which a soundwave is distributed in the space. If sound pressure is uniformly distributed throughout the space, the sound is said to be well diffused

Diffusion

If a specular reflection from a hard flat surface is giving a problematic echo then an acoustic diffuser may be applied to the surface. It will scatter sound in all directions. This is effective to eliminate pockets of noise in a room.e applied to the surface. It will scatter sound in all directions. This is effective to eliminate pockets of noise in a room.

For more information please visit the following links:

https://www.physicsclassroom.com/class/sound/Lesson-3/Reflection,-Refraction,-and-Diffraction
https://www.acousticalsurfaces.com/blog/acoustics-education/what-is-sound-diffusion-and-absorption/

Decoupling

Decoupling is a method to reduce the area of direct mechanical linkage between structure and substrate. Such as walls and the applied finishing materials.

This process interrupts flanking transmissions that tend to travel through a structures’ own rigidity and connectivity from start to end.

Damping

It is the process of reducing resonance in an enclosed structure by absorption, reflection or diffusion. Absorption will reduce the overall sound level of the structure and redirection reduce the coherence thereby making the unwanted sound harmless.

Distance

The further away an object or a space is from a sound attenuating source the more isolation or blocking it will have from incident sound waves. 

This is because soundwaves lose energy while travelling through any media and therefore dampens by diffusion, reflection & absorption over a finite distance.

Mass

Adding dense material for soundproofing can help reduce transmission by increasing the material molecules present. 

Soundwaves will have to expend more energy through dense substances thereby reducing its impact on the space which requires sound proofing. 

Ways to make a soundproof wall

The following are some of the most effective ways to soundproof a wall

Acoustic Caulk

It’s basically a paste type of solution which is also commonly referred to as an acoustical sealant. It helps in sound dampening all those areas where gaps are found.

Acoustic Curtains

Hanging soundproof drapes reduces sound reflection off of glass window panes, partition walls and doors which can significantly improve acoustic comfort and prevent sound leakage

Noiseproofing compound

It works in a similar way and can be considered as an acoustic caulk considering it can absorb 90% of noise and is suitable for application on either side of the floor.

Green Glue Noiseproofing is a regularly used compound used for this purpose which can be applied between any two hard surfaces or between the studs and drywall.

It reaches its peak noise dissipation performance after 30 days of application.

Mass Loaded Vinyl (MLV)

MLV is a thin & flexible material with a very high STC( Sound Transmission Class) Rating specifically used for blocking soundwaves.

It doesn’t absorb soundwaves but rather it reflects the sound dampening the sound waves each time it bounces off it since it adds additional mass.

MLV also has a high thickness to mass ratio due to it containing Calcium Silicate which creates a strong sound barrier. 

Additional Drywall

Using resilient channels to affix atop the existing wall, this can be very effective in creating a substantial sand barrier by the decoupling phenomenon as described in the previous section.

Installing additional drywalls can be expensive, however this is the most effective method in making a wall soundproof

SoundProof Wallpaper/Paint

According to a research study, soundproof wallpaper & paint can reduce upto 30% noise. However, it is better advised to use soundproof paint in conjunction with the other methods to extract maximum effectiveness when it comes to soundproofing

Acoustic Foam Panels

Composed of compressed mineral wool or foam, sound absorbing acoustic foam panels absorb sound waves to reduce general noise, clarify speech and limit reverberation in walls within enclosed areas. 

It reduces sound reverberation, echos & volume which make it great material for soundproofing a wall. 

Leverage large and soft furniture

Adding BookShelves, Sofas, Cabinets etc can not only help improve the aesthetics of an apartment but reduces sound reflection and maintains acoustical isolation. 

All this and without adding a dime to the expenses one has to invest in soundproofing using specialty materials and equipment.

Conclusion

This blog addresses the ways in which sound can infiltrate through a wall, the performance metric information an individual needs before opting for soundproofing a sliding door. Also the type 4 types of wood material which need to be considered in the pre-construction phase that provide effective sound blocking and absorption.

Finally, what are some of the main ways that an individual can soundproof a wooden floor and the effectiveness of each method.

If you have any questions or comments please let us know.

Frequently Asked Questions: How to make a soundproof a wall

Is Velvet a good sound absorber?

When it comes to sound-absorbent textiles, most experts agree that suede and velvet are two of the greatest options. Because these textiles are dense, porous, and have rough surfaces, they may absorb a substantial quantity of acoustic energy.

Is soundproofing expensive?

As we mentioned above, there are countless different methods to soundproof pretty much any type of wall. Luckily, each of these methods differs in how simple they are and how cost-effective.

Still, it doesn’t always have to mean that investing more money would bring better results. Soundproofing is essentially just adding mass to your wall.

That’s something you can do in many different ways depending on the results you want and how much you care about the aesthetic aspect.

Can I soundproof a wall that has a window?

Any wall can be improved, even the one with a window or door. It might require some extra work since you’d have to work around those holes but it can still be done.

Every way of soundproofing we’ve mentioned above can also be done on a wall that has a window or door. You can add drywall, foam panels, paint or anything else to it. Still, keep in mind that windows are far less soundproof than walls so unless you treat them too, the noise will still find its way in your room.

There are different ways to soundproof doors and windows so you’d probably have to do that as well in order to get satisfactory results.

What situations require soundproofing?

The basic reason to soundproof a room or a space is to prevent your current activity from getting disturbed.

This could be in situations such as:

In a bedroom to snooze in absolute silence. A good night’s sleep can keep a person more focused and active for the day and revitalise the senses.

At a recording studio where ambient sounds are detrimental to the recording process which could require multiple retakes and order expensive post processing to filter out such noises

In meetings or during a conference where sound bleeding cannot just be a disturbance but a leakage of confidential or privileged information not suitable for any other audience. Also, it can prevent clear passage of sound and cause incorrect information to be registered by the audience.

Personal office spaces and study rooms greatly benefit from sound isolation as much like good night’s sleep it can help to improve and sustain focus on the task at hand and prevent distractions.

References:

Soundproofing Store: https://www.soundproofingstore.co.uk/how-to-soundproof-my-wall-against-noisy-neighbours

Better Soundproofing Team. (2021, August 22). 15 Ways of Soundproofing Existing Interior Walls Without Removing Drywall. Retrieved from Better Soundproofing: https://bettersoundproofing.com/soundproofing-existing-walls/

Family Handyman Team. (2020, January 21). How to Soundproof a Room. Retrieved from Family Handyman: https://www.familyhandyman.com/project/how-to-soundproof-a-room/

Joe. (2017, May 10). How to Soundproof a Wall Cheaply (Existing or New) [2022]. Retrieved from SoundProof Silence: https://soundproofsilence.com/how-to-soundproof-a-wall/

Mike. (2021, October 3). How to Soundproof Walls. Retrieved from Noise Stop Systems: https://www.noisestopsystems.co.uk/how-to-soundproof-walls/

SoundProof Cow Team. (2019, August 21). How to Soundproof a Wall. Retrieved from SoundProof Cow: https://www.soundproofcow.com/soundproofing-101/how-to-soundproof-a-home-2/how-to-soundproof-a-wall-2/

SoundProofing Company Inc. (2019, February 12). Soundproofing Walls. Retrieved from SoundProofing Company: https://www.soundproofingcompany.com/soundproofing-solutions/soundproofing-walls

TOHT, D. (2018, June 12). Shhh! 9 Secrets for DIY Wall Soundproofing. Retrieved from HouseLogic: https://www.houselogic.com/remodel/remodeling-tips-advice/soundproofing-walls/

Vila, G. T. (2021, October 24). Glenda Taylor and Steffani Cameron and Bob Vila . Retrieved from The Best Ways to Soundproof a Room Without Tearing Down Your Walls : https://www.bobvila.com/articles/how-to-soundproof-a-wall/

W, T. (2020, June 3). Soundproofing vs Sound Absorbing – What’s the Difference? Retrieved from ACOUSTICAL SURFACES, INC.: https://www.acousticalsurfaces.com/blog/soundproofing/soundproofing-vs-sound-absorbing