Does soundproofing foam actually work?

Foam is not enough to function well for Soundproofing because it has insufficient mass for sound blocking but is an excellent choice for sound absorption. As a result, the idea that acoustic foam is a soundproof foam is a myth!

It’s shocking to find many sites and groups claiming that foam is a cost-effective and efficient soundproofing material.

Soundproof Foam

People don’t grasp the distinction between sound-absorbing and Soundproofing, which leads to the misperception that foam is soundproof.

It’s reasonable to believe that if sound-absorbing materials like foam absorb it, there won’t be any left to escape the room.

Sound isn’t like a fluid that can be absorbed and contained in a sponge. It’s important to understand how sound acts in this situation. Sound waves are vibrations, and when they hit a surface, they cause it to vibrate.

Sound vibrates rather than ‘passes’ through a surface. These vibrations are transmitted to the opposite side, which is how sound travels through surfaces.

soundproof foam

Sound absorption vs. sound blocking

It’s crucial to know the distinction between absorbing and blocking sound before moving on to the working of sound insulation foam. Although both names are frequently used interchangeably, there are significant differences between both.

Various materials react differently to sound. Different varieties of acoustic foam can block out the external sounds or absorb sounds within a room to lessen reverberations. As a result, it’s critical to understand your goals before investing in any soundproofing solution.

Also Read: Does Soundproof Foam work both ways?

Points to Address for Soundproofing

Sound is divided into two types.

  • Airborne noise, like TV noise and people talking, is the most prevalent. 
  • Vibration impacts noise, including live musical instruments and machines vibrating.

To successfully soundproof a wall, you must:

  • Increase the wall’s mass – This is usually accomplished by including various high-density goods.

But when sound reaches a wall, it transforms into vibration and power; therefore, mass alone won’t be able to fix the problem. You should also:

  • Increase the wall’s ability to absorb sound and vibrations. Also, adding mass will have a little effect if this is not done.
  • Use various high-mass materials. Because various materials perform better at different sound frequencies, combining high mass materials always outperforms just utilizing the same kind of material.
  • Because the vibration created is too intense to be blocked by attaching to the existing structure, you must also detach the new wall from the current one for a louder, more potent sound energy.

The working of soundproofing foam

Sound absorbing foam

Sound absorbing foams are softer and light-weighted than sound blocking ones. This open, flexible structure functions as a natural sound absorber, preventing sounds from echoing off hard surfaces. It accomplishes this by turning the existing sound energy into heat and limiting sound waves’ ability to bounce back to a space.

This foam type can also improve the room’s acoustics based on its use. Sound-absorbing foam cuts into wedge forms and can then be used to enhance the sound quality by manipulating vibrations. Installing the visible foam tiles and wall panels is a common example of how echo can be decreased.

Sound blocking foam

Sound-deadening foam is used to keep sounds from traveling through walls. This necessitates materials that are opposed to the soft, lightweight foam commonly found in recording studios.

Foams with a tighter cell structure are thus more prevalent in this application, as the denser the foam, the fewer possibilities soundwaves have of passing to the other end. If you’re having trouble with sound coming in through the surfaces from other building sections, you’ll need to shut it out.

Conventional Foams vs. Acoustic Foams

Conventional foams and acoustic foams are not interchangeable because they are manufactured for different purposes. If you’ve ever seen foam inside on your sofa or any other chair, it’s similar to regular foam.

On the other hand, acoustic foam is designed specifically for deadening or absorbing sound waves and absorbing a large amount of heat.

It is a little more robust than traditional foam as it’s likely to be used in more popular areas where bigger groups of people may congregate, increasing the likelihood of striking the wall where an Acoustic foam is installed.

Acoustic foams have been thoroughly evaluated to aid in sound absorption, vibration reduction, and echo reduction to the greatest extent feasible.

Also Read: Does it matter where you put acoustic foam?

Cost of Soundproofing Foams

Foam wedges are less expensive than fiberglass insulation panels and are preferred for recording studios. This is because a fiberglass insulation board requires a frame to prevent it from breaking, and the panel must be coated with fabric to prevent insulation fibers from flying off.

Foam doesn’t need a frame or fabric because it’s sturdy enough to resist light loads and doesn’t have any flying fibers.

You can buy these foams at an average price of $1.50 to $5 per sq. ft.

What are the alternatives for Soundproofing?

1.      For walls

  1. Extra Drywall

Sound transfer can be reduced by adding an extra layer of drywall. A drywall sheet with a thickness of 5/8″ weighs 2.31 pounds for each square foot. That’s a lot of bulk, and it’s an excellent substance for limiting sound transmission. Returning to foam, different types and thicknesses are based on the grade and the type.

The foam would have to be a few inches thick to equal the bulk of drywall. It is less expensive and has a large amount of mass. However, because it requires a lot of time and craftsmanship to install and structural modifications, it is not a choice for rental residences.

  1. Mass Loaded Vinyl (MLV)

Mass loaded vinyl, unlike foam, is both flexible and dense. It’s an excellent approach to limit sound transfer if you do not wish to deal with the inconvenience of drywall installation or if you live in a rental flat where structural changes are prohibited.

Again, standard ‘soundproof’ foam is not perfect for an MLV’s mass. It’s simple to put together and has a larger density and bulk. It can also be employed when adding more drywall isn’t an option. It is, however, a little more pricey. On Amazon, these cost around $2.5 for each square foot.

  1. Damping Compound

Increasing Soundproofing’s effectiveness by using a damping compound such as Green Glue is an amazing idea. The damping compound gets sandwiched between the existing ceiling or wall and the new drywall or Mass Loaded Vinyl (MVL).

It doesn’t take up any more space because it’s a fluid sandwiched between two rough surfaces, and it’s also highly cost-effective. However, it will undoubtedly increase the costs and is a little untidy to apply. Furthermore, it takes a long time to curate.

2.      For floors

  1. Soundproof Underlayment

This is the most effective soundproofing method. A 3/8″ thick underlayment, like the Serena Mat, would weigh around 1.4 pounds for each square foot. It’s simple to put together and constructed of recycled materials. It has a high level of effectiveness (much greater than foam) and can be attached straight to engineered wood. But it is a little more pricey.

  1. Cork Underlayment

If you don’t wish to spend on soundproof underlayment, you can choose a more cost-effective ‘sound deadening’ alternative. Cork is a popular underlayment because it’s much more effective than foam and costs half a dollar or less.

It is both cost-effective and simple to put in place. It can also be used on a variety of floor surfaces. But, the only drawback is that this solution is not as effective as MLV and Serena or Acoustik Mat, but it is significantly superior to foam. It’s also prone to dampness, necessitating a plastic protective coating.

3.      For doors

  1. Communicating Doors

Having communicative doors is the best way to reduce sound transfer. A set of two communicating doors is installed with a space between them. The air gap will provide an insulating layer, which will be quite useful for Soundproofing. Installing interconnecting doors can increase the STC rating from 30 to 55. 

  1. Replace the Door

Another alternative is to install a solid-core door in place of the hollow-core door. Solid core doors perform better than solid wood ones, and they are less expensive in comparison. However, in terms of Soundproofing, it will fall short of the communication door.

  1. Soundproof Curtains

It would take some time, money, and other resources to install communication doors or replace the door. Noise reduction curtains are named because they dampen sound, but they don’t do much more. They’re also a lot better than foam.

These curtains are substantial and functional, but they aren’t as good as the other options. Nonetheless, having them is preferable to having none at all.

4.      For windows

  1. Double or Secondary Glazing

A double-layered window having an air gap between them would be the best option. The air gap acts as an excellent sound insulator. Laminated or acrylic glass are the types utilized for this. Your present window would have to be removed to install a double-glazed window.

The issue with such windows is their high cost. Secondary glazing, in which your existing window serves as the initial layer and the second layer of acrylic, laminated or acoustically laminated glass is added, is an alternative. Soundproofing will become more effective with laminated glass than with acrylic.

  1. Install a Window Plug

This is a popular choice among those who own a home theater or studio. A window plug is a simple approach to limit sound transmission by adding mass to the window. It’s also an effective technique to soundproof windows without replacing them. A window plug is essentially a box filled with insulation that fits in the gap over the window sill and exactly matches the window’s measurements.


For a space to be soundproof, it must absorb sound from within the room and block sound from the outer world. For enterprises that require a controlled environment, this is a somewhat frequent undertaking, albeit achieving the appropriate mix can be costly and time-consuming.