You might have seen these in Home theatres, KTVs, musical instrument rooms, recording studios, and even meeting rooms but what are they?
These wedge-style angled designs are actually called Sponge Acoustic Foam which helps with noise reduction ensuring optimum sound absorbency. This lightweight airy foam is used to absorb mid to high frequencies and control as well as trap echoes in the room mainly for professional acoustic control, sound dampening, and noise reduction – reducing reverb, echoes, and sound waves. They are usually installed on the walls or ceiling as a finished surface in the room. Made from open-cell polyurethane foam, the sponge is intended to be a pyramid shape because it gives a little diffusion; making the sound more dynamic and powerful.
They can come in different sizes and thicknesses, colors, shapes, and even textures which can be attached to walls, ceilings, doors, and other features of a room. The only downside of polyurethane foam is its fire properties – it releases a high smoke level when burned therefore unsafe in event of a fire.
It is commonly used in our Audio Suite Room to do VoiceOver (VOs) as well as audio mixing. This is essential to record dialogues and the raw voice of the talents off-camera typically used during the post-production process. Productions use voice-over narration to provide additional context to the visuals or as a form of guided narration.
As much as they reduce reverb, Sponge Acoustic foam does not block sounds because sponges are usually fluffy and porous in nature which still allows sound to get through. They rather absorb sounds and prevent sound from continuing to bounce and echo back into the room by converting them to heat energy. Regardless of the type or thickness of foam used, you will still be able to clearly hear your friend outside as if there were no wall in front of you even though the door is closed. Take into account that the sponge is light and airy. And sound waves travel through the air that’s why we can still hear voices from outside. The concept is similar to when the sponge is dipped into water, water will fill up the holes of the sponge and absorb them. Therefore, Sponge Acoustic Foam will not entirely soundproof a room but rather reduce the sound from outside or inside. They are usually placed in a facility that is placed at corners of the room or wherever optimal sound mixes are needed as bass traps to minimize sound echoes.
Image: Mass Loaded Vinyl Insulation
To further enhance the blocking of the soundwaves, there is a need to install a Sound Blocking Foam to prevent noise from traveling through walls. These foams are rather thicker and denser than the Sponge Acoustic Foam and usually are installed between 2 walls. Examples of sound-blocking options are Fabric-wrapped acoustical panels, Echo Eliminator, Cementitious wood-fiber panels, and many more. They absorb sounds more while thermally insulating and reducing echo and reverberation through sound absorption.
Acoustic Foam is a cheaper alternative to “soundproof” walls or decreases the volume of the desired area because of its price compared to Sound Blocking foam. We hope you enjoyed reading and benefitted from the blog. Stay tuned for more blogs.