No More Confusion! A Guide to Differentiating Soundproofing, Sound Absorption, and Sound Insulation

What is Soundproofing?

Soundproofing refers to blocking external noise or preventing internal sounds from leaking out. Surprisingly, there is no material specifically called “soundproofing material”! What is often referred to as “soundproofing material” actually includes products like sound-absorbing materials and vibration-damping materials designed to control the behavior of sound.

By cleverly combining these materials, you can effectively reduce noise. In other words, understanding sound absorption and sound insulation is crucial for effective soundproofing. Without this knowledge, it’s difficult to create an efficient soundproof room or soundproof cover.

What is Sound Insulation?

Sound insulation is the process of blocking sound from passing through walls, doors, or other barriers. It acts as a “sound barrier,” preventing noise from traveling to the other side. The ability to block sound is referred to as “Transmission Loss (TL),” with common materials including steel plates, concrete, and gypsum boards.

When people think of “soundproofing,” they are often referring to sound insulation.

What is Sound Absorption?

Sound absorption refers to reducing reflected sound by allowing sound to enter porous materials, where it spreads and converts into heat. Porous materials have numerous small holes, creating a structure that traps sound within. Common sound-absorbing materials include glass wool, rock wool, and urethane foam.

The performance of sound-absorbing materials is indicated by their “absorption coefficient.” However, measurement methods can yield different results, so it is essential to compare materials under the same conditions.

Secrets to Effective Soundproofing

The key to soundproofing lies in combining sound insulation, sound absorption, and vibration damping effectively. To enhance sound insulation, it is fundamental to make sound-insulating materials heavier and thicker. This principle, known as the “Mass Law,” dictates that heavier materials block sound more effectively.

However, relying solely on heavy materials can be costly and inefficient in construction. Therefore, combining sound-absorbing and vibration-damping materials to balance effectiveness and cost-efficiency is the core principle of soundproofing.