Yoga mats interact with sound in distinct ways, like everything else in your studio or home. All materials influence sound waves to varying extents, including transmission, blocking, reflection, and absorption. However, you may have heard that yoga mats absorb sound and wondered if there was any scientific proof to this.
Yoga mats really do absorb sound but to a limited extent. Furthermore, not all yoga mats are equally effective at absorbing sound or vibration. In particular, yoga mats made with natural rubber are better at absorbing sound and vibration than mats made of other materials.
Keep reading to learn more. In this article, I’ll explain the science behind how yoga mats absorb sound.
How Do Yoga Mats Absorb Sound?
Yoga mats absorb sound by trapping and damping the audio waves in the material. Yoga mats made of natural rubber have innumerable cells that can absorb some sound energy. Also, the cell structure, density, and tortuosity reduce the momentum of sound waves.
The material combination and composition and other features, such as thickness, determine the sound absorption capacity of a yoga mat. Keep in mind yoga mats absorbing sound to any extent should not be equated to soundproofing a given space.
The only way to understand how yoga mats absorb sound is by exploring the science of audio waves and the gradual loss of energy, including conversion. A yoga mat’s sound absorption is nominal compared to spatial soundproofing, but it’s an ancillary benefit if noise is a concern.
The Characteristics of Sound Waves
Sound waves originate at a source and travel through a medium, including air, water, and materials. A medium may transmit the sound waves without altering its frequency (Hertz or Hz) and intensity or loudness (decibel or dB). However, that does not happen in reality.
All mediums interfere with the transmission. Thus, sound waves lose momentum, get partially transmitted and absorbed, and are partly or entirely reflected. For instance, modified concrete does not absorb or transmit sound waves. Instead, it reflects the sound waves upon impact.
In contrast, many mediums have more than one interaction with sound waves. For example, air and water transmit, reflect, and absorb sound waves, depending on audio frequency, pressure, and other factors, including medium composition.
Likewise, natural rubber and cork can absorb sound waves and alter the intensity or loudness, thus dampening the noise. Therefore, yoga mats with natural rubber or cork can reduce ambient noise and specific sounds in a studio or room, subject to the material composition and quality.
The Loss and Conversion of Sound Energy
Sound waves lose energy during transmission through a medium and interaction with various objects. This energy loss is essentially a conversion. The oscillating motion of the sound waves excites the molecules of a medium or object. And these molecules start to vibrate as a result. Thus, the sound energy is converted to kinetic energy, and in small proportions, heat energy.
When the medium is air, sound waves change the atmospheric pressure by causing the gaseous molecules and particulate matter to vibrate. These reactions convert sound energy to kinetic energy and nominal heat energy. Thus, the sound waves lose intensity and momentum. In effect, a sound wave eventually dies instead of oscillating infinitely and traveling forever.
Yoga mats, whether natural rubber or cork, have countless cells with sealed air pockets. Thus, the cell structure, material density, intermolecular force, and flow resistivity absorb some sound waves, alter the others interacting with the mat by creating resonance, and may reflect a few.
How Does a Natural Rubber Yoga Mat Interact With Sound?
Natural rubber interacts with sound by absorbing some of the energy and reducing the waves’ momentum. These effects are due to the strong intermolecular force, tiny cell size, and high tortuosity of natural rubber. Also, thicker rubber absorbs more sound.
Visualize a layer of natural rubber, not very different from what you get in regular yoga mats. The rubber layer has a strong intermolecular structure consisting of millions of tiny cells forming an enormously complex web. When audio waves cause these molecules to vibrate, the intermolecular force of natural rubber uses a lot of sound energy for the required kinetic energy.
Also, sound waves navigate the complicated structure and cells of natural rubber, thus losing energy, intensity, and momentum. In effect, the rubber in your yoga mat absorbs some sound. However, this absorption happens only in the small space of the sound’s interaction with the rubber. There is no grander effect of the yoga mat on the sound waves elsewhere in the room.
The Sound Absorption Coefficient of Natural Rubber
Mathan Sambu and his team at the Mechanical and Manufacturing Engineering of the Universiti Tun Hussein Onn Malaysia studied the physical properties and acoustic performance of a few nonwoven fiber composites of Arenga pinnata and natural rubber. These findings are published in the Asian Research Publishing Network’s Journal of Engineering and Applied Sciences.
The study concluded that a composite of 80% Arenga pinnata and 20% natural rubber, which is essentially using the latter as a binder, increases the sound absorption coefficient to as much as 0.98. This sound absorption coefficient varies for different frequencies, dropping to 0.9 for some.
For perspective, soundproofing materials should have a sound absorption coefficient higher than 0.75. The study revealed that Arenga pinnata is incapable of attaining that level of sound absorption without natural rubber as a sound absorber and dampening enhancer.
Natural rubber increased the composite’s density, tortuosity, and airflow resistivity while reducing porosity. Thus, natural rubber is an effective sound absorbing material and can even be used for soundproofing in different compositions, like the composite with Arenga pinnata.
However, you may not experience a sound absorption coefficient of 0.98 or even 0.9 with a regular yoga mat made of natural rubber. Still, a yoga mat can reduce the immediate noises of a person exercising and practicing yoga, and such reasonable sound absorption is desirable.
Natural Rubber Yoga Mats Absorb Vibration
Rubber, both natural and synthetic, is exceptional at absorbing vibration. This strength of rubber makes it ideal for widespread applications as gaskets, seals, and packaging. You are probably aware that sound creates vibrations and vice versa. Thus, a rubber yoga mat absorbing sound due to vibration and vibration caused by sound can be a valuable asset in your studio or home.
Yoga mats made of natural rubber are more than capable of absorbing the sounds of footsteps, postures, and lightweight accessories, like a cork block. Also, such yoga mats will absorb some noise from the audio speakers, television, and other devices, but this effect is usually negligible.