01. What is Sound Insulation? Basics

Sound insulation literally means “blocking sound,” but it might be more accurate to think of it as “reflecting sound.” The degree of sound insulation is referred to as the “insulation level” or “sound insulation value.”

Let’s look at how to increase sound insulation. Since sound isn’t visible, it can be challenging to conceptualize. To help, I’ve created a simple illustration below.

*Think of it like throwing balls (representing sound) against a soundproof wall; the wall that reflects more balls has a higher level of sound insulation.*

A thicker, heavier, harder soundproof wall reflects more balls, like a solid concrete wall, which bounces the balls back…

If you throw balls against a thin plywood board, they don’t bounce back as much, right?

Using thick, heavy, hard materials is one way to increase sound insulation.

Another way is sealing tightly—like a sealed water bottle with no leaks. If a bottle has even a tiny hole, it will leak, right? Sound is the same. This is why soundproof room doors are designed to seal tightly, like a bottle cap, to prevent sound from escaping.

By combining (1) thick, heavy, hard materials with (2) a tight seal, you can create a highly sound-insulated space. A submarine is a good example, made of steel and tightly sealed.

But you can’t just put a submarine in your home if you want to sing loudly without disturbing others. That’s where creativity comes into play in real soundproof room construction.

One solution is to build a soundproof room within another soundproof room, like a nesting doll. This is often called a “box-in-box” approach. With careful calculations, this setup allows for lighter materials, making it suitable for multi-story buildings where heavy materials aren’t feasible, and it also keeps costs down.

A second technique involves combining various materials in multiple layers, using complex principles to create a soundproof structure. It sounds complicated, right? If you’re interested, please ask directly. Soundproofing specialists use these methods to create lightweight, high-insulation designs.

Summary:

Summary: What is Sound Insulation?

Sound insulation is the act of blocking or reflecting sound.

1. The degree of sound insulation is referred to as the “insulation level” or “sound insulation value.”
2. Thick, hard, heavy materials have a higher sound insulation value.
3. Thin, soft, light materials have a lower sound insulation value.
4. Without a tight seal, sound can escape.
5. Using various methods, you can create lightweight structures with high sound insulation.