The Differences in Sound Control: Acoustical Insulation vs. Sound Dampening Materials
Despite their common purpose to reduce noise, acoustical insulation and sound dampening materials are quite different in terms of the materials they are made from, the way they operate, and the applications in which they can be most effective. Acoustic management materials—depending on whether they are being used in vehicles, buildings, or industrial applications—need to have certain properties to adequately achieve the best performance, which is why understanding the primary differences between acoustical insulation and sound dampening materials is crucial when working in these spaces.
What are the exact differences, compositions, properties, and applications of acoustical insulation and sound dampening materials? This technical overview will help you make an informed decision no matter what application you are working with.
What are Acoustical Insulation Materials?
When referring to acoustical Insulation, we’re fundamentally talking about soundproofing—preventing the transmission of sound between different areas. Acoustical insulation materials are designed to reduce sound transmission from passing through walls, ceilings, floors, and other surfaces, thereby maintaining a quieter environment in the designated space.
Acoustical Insulation materials are typically made from fibrous substances like spunbond polyester, polypropylene, or open cellular foams. These materials are often porous and fibrous, and they have a structure that allows them to absorb sound waves. Acoustical insulation is generally thicker than sound dampening materials to enhance its sound-blocking capabilities. When sound waves enter the material, they move through tiny air pockets within the material. The material's fibers or cells convert the sound wave energy into heat energy, thus diminishing the strength of the sound as it passes through.
Acoustical insulation materials are known for their:
High internal integrity
Resistance to flammability (UL 94V-0 flame class rating)
Excellent dielectric strength: they shield against electrical surges
Chemical resistance
Low weight
Effectiveness at blocking sound transmission across a range of frequencies; they are especially effective at mitigating higher frequency sounds.
In order to be most effective at sound insulation, the materials must have:
Porosity: Allows for the absorption of sound waves.
Density: Heavier materials are generally more effective at soundproofing.
Thickness: Typically, the thicker the insulator material the better the sound insulation.
3M™ Thinsulate™ is a common acoustical insulation material made from polyester and polypropylene, because it’s made of non-woven sound absorbing fibers that create a quieter environment. It delivers a high acoustic absorption per unit weight and is used extensively throughout the automotive and transportation industries.
Acoustical insulation materials are most commonly used in:
Vehicle trim and panels
HVAC sound absorption
Instrument panels
Can provide some thermal insulation
What are Sound Dampening Materials?
Sound dampening focuses on reducing or weakening the vibrations and movements that cause sound. The process works by dissipating the energy of sound waves or vibrations, converting it into a negligible amount of heat, thereby reducing the sound's amplitude and impact. Sound dampening materials absorb sound waves and vibrations directly at their source, reducing their energy and preventing them from emanating further.
Sound Dampening materials can vary widely in composition. They often include PSA (pressure-sensitive adhesive) backed foams, such as 3M™ ISOLOSS™, and specific damping products made from denser polymers lined with aluminum, glass cloth, or similar materials. These compositions are adept at dampening sound energy and are generally viscoelastic in nature. The materials are often applied directly to vibrating surfaces to mitigate sound at its origin.
Sound dampening materials are known for their ability to:
Reduce NVH (noise, vibration and harshness)
Stop sound at the source
Weathering, UV, and moisture resistance
Operating temperature ranges between –5° to 176°F
Effectiveness at reducing low-frequency noise and vibrations, like those produced by machinery or traffic
Thinner materials
Sound dampening typically requires much less material to be used, but the materials can be more expensive than sound insulation materials. There are flame retardant options available, but if thermal insulation or flammability is a concern for you, it may be better to use acoustical insulation fabrics.
Sound dampening materials are most commonly used in applications that include:
File cabinet doors
Truck liners
Vehicle side panels
Any application that needs to dampen NVH
Applications that produce low frequency sounds
Custom Sound Deadening Materials
Whether you’re looking for sound insulation, sound proofing, NVH reduction, or any other acoustical control on your application, we can help customize an effective solution for you. All our sound deadening materials can be provided in slit rolls or die-cut parts based on your specific needs, and pressure sensitive adhesives and/or film tape layers can be added to improve performance and simplify manufacturing.