Gypsum board is a dense material, and its sound-insulating ability is primarily governed by the law of mass. Simply put, the heavier and denser the material, the greater its ability to block sound transmission. Sound waves expend a significant amount of energy trying to pass through gypsum board, thereby isolating sound - particularly mid- and high-frequency sounds.
If you're constructing a dividing wall between a home office and a bedroom, or working to reduce noise transfer from one room to another, then gypsum board is likely the base material for a soundproof wall or ceiling system.
A single layer of gypsum board has limited soundproofing capabilities. Typically, professionals utilizing a double layer of gypsum board with soundproofing pads or insulation will create a system that optimizes sound insulation performance.
2. Gypsum Board's Weak "Sound Absorption"
Sound absorption refers to the process where sound waves convert to heat energy when they strike a surface without being reflected. Sound-absorbing materials are generally soft, porous, and fibrous, including materials such as rockwool, glasswool, polyester fiber, or foam materials. As the sound waves move into the infinite pores of the material, their energy is dissipated in the material through friction.
Disadvantages of Gypsum Board:
The surface of gypsum board is hard, smooth, and dense. When sound waves strike it, nearly all are being reflected back into the room rather than absorbed. It is similar to clapping your hands in an empty room, in which you hear a loud echo because the sound reflects in between the hard walls, floor, and ceiling of the room. Gypsum board walls function as such reflective surfaces.
3.Gypsum Board Composite Systems (for Sound Insulation)
If you want to stop the sound from travelling to the adjacent rooms, the best route is to use gypsum board in conjunction with some type of soundproofing insulation (like rock wool or glass wool), as a wall or ceiling.
The gyspum board adds mass to reduce sound transit, while the ocnditioning of the insulating material absorbs sound by filling the cavities. The two together present a signficant improvement in overall sound insulation performance.
4.Adding Specialized Sound-Absorbing Materials (for Sound Absorption)
If you want to limit sound and echo in a room, put specific sound-absorbing materials on your drywall ceiling or walls. Examples include:
Acoustic panels: Available in different options and styles; they can be glued to or hung on existing drywall and other surfaces.
Acoustic foams are sometimes wrapped in decorative fabric; they provide some aesthetic quality as well as functioning as acoustic products.
Also: Heavy draperies, carpets on the floor, and upholstered furniture can also provide added sound absorption.