When on a commercial flight, you’re constantly surrounded by noise from the plane’s exterior and the plane itself. However, you might not have ever noticed – thanks to acoustic decoupling. To make for a quiet cabin, acoustic decoupling is a form of soundproofing in which you separate two sides of a material to provide acoustic efficiency. This sound control technology is used in planes to reduce aircraft cabin noise and provide passengers with comfortable flights worldwide.
Acoustic Decoupling is the Answer to Excessive Sound
Both aerodynamics and the aircraft itself generate external noise on a flight. In the case of aerodynamics, commercial jets can get up to speeds of Mach 0.85, resulting in furious winds whipping around the outside of the aircraft and producing a significant amount of noise. Jets themselves come fully stocked with pumps, hydraulic actuators, electrical equipment, and more, as well as the constant whir of the engines. These noises will vary from aircraft to aircraft. Still, it can generally be categorized as a substantial sound that requires insulating materials of very high acoustic efficiency to provide the desired comfort and verbal communication levels. Passengers and crew benefit from a quiet aircraft that can reduce jet engine noise levels with sound control technology.
Highly efficient acoustic decoupling attenuator materials include mass-loaded flexible barriers and non-woven absorbers. They can be used either separately or together, depending on where they are applied in the aircraft. Our Durasonic Noise Reduction Materials are widely used acoustic decoupling attenuators designed to function as a barrier curtain, partition, composite barrier/absorber, or even a vibration-damping material. On top of the acoustic efficiency canceling aircraft cabin noise, our noise reduction acoustic decoupling materials offer flame resistance for the utmost security in fire safety – meeting FAR25.853(a) and FAR25.856(a) requirements.
The Path of Sound Waves Through Material Layers
The following diagram shows how sound is blocked and absorbed by the different layers of acoustic decoupling materials.
How Acoustic Decoupling Boosts Sound Transmission Loss (STL)
As shown in the diagram above, the sound barrier on the sound incident side of the acoustic decoupling first reflects a portion of the sound. The non-woven material in the middle then absorbs some of the sound not reflected by the first barrier. The second sound barrier further reflects transmitted sound, which the middle layer has not entirely absorbed. The combination of these three components working together allows only a low level of transmitted sound to move on.
Acoustic decoupling materials deliver improved STL at the same weight as conventional single-layer, mass-loaded fabrics — or often, less weight and space. With acoustic decoupling that takes up less space at a lower weight, the aircraft will not be weighed down. If your aircraft is weighed down it can result in a myriad of problems.
What is the Decibel Level of an Aircraft?
The decibels of a jet engine can measure anywhere between 120 and 140 decibels. These sound levels are what make acoustic decoupling technology so important. Sounds above 85 decibels have the potential of causing hearing damage to passengers and workers. With prolonged exposure to these sounds without the aid of sound control technology, aircraft crew and passengers who fly extensively are at a much greater risk of hearing loss and damage. Experts have shown that it only takes two hours for hearing to become damaged when the decibel level is at 91 decibels. Without the proper sound barrier protection, jet engine noise levels can result in disastrous consequences.
Acoustic Decoupling Sound Materials Take Sound Control Technology to the Next Level
At Duracote, our decoupling sound control technology interrupts sound waves more effectively with our new acoustic decoupling attenuator designs. Acoustic decoupling utilizes both sound absorption and sound blocking for the best soundproofing of aircraft cabin noise. Our designs typically consist of two flexible polymer barriers with non-woven absorber insulation placed between them. You can choose from our single, double, or extra-strength barriers. These barriers are designed to mate with the aircraft’s cabin wall or other existing barriers within the jet and result in the decoupling of sound for a quiet cabin.
Acoustic Decoupling Outperforms Other Materials in High-Frequency Ranges
As we age, we start to hear higher frequencies less as a natural result. Normal hearing range in adults is typically more tuned to lower frequencies, but children and infants still retain their ability to hear high-frequency sounds. A jet engine produces vibrations in the high-frequency range and may still be heard by children and infants. At Duracote, we aim to provide products that can benefit people of all ages. Duracote decoupled composite better protects against high-frequency sound and creates a quiet aircraft for all passengers.
Dura-Sonic® Decoupled Sound Control Technology Optimizes Acoustic Levels for a Quiet Airplane
Duracote’s decoupled technologies include combinations of Dura-Sonic or Dura-Trim with a foam, nonwoven, or fiberglass absorber depending on the necessary weight and flammability requirements of a specific aircraft. Our acoustic decoupling designs use a variety of barriers and absorbers to develop composites that meet desired sound transmission loss targets in different aircraft.
Critical factors in Duracote custom acoustic decoupling designs include materials selection, weight positioning of different materials, and the total thickness of the composites. Decoupling solutions can also utilize a composite barrier & absorber that mates with a cabin wall or other existing barrier.
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Duracote. New Ideas. New Ways to Make Materials That Fly.
For over 70 years, Duracote has been producing top-rated products to aid in acoustic efficiency. With high-quality materials and expert knowledge, we have created the very best in acoustic decoupling to aid in maintaining a quiet aircraft. View our full range of products today, and provide the very best in passenger enjoyment.