What type of insulation is commonly used in walls for soundproofing?

Fiberglass insulation is often used in walls for soundproofing due to its ability to reduce sound transmission between rooms. The material consists of fine glass fibers that trap air, which not only provides thermal insulation but also dampens sound vibrations. This characteristic minimizes noise transfer, making it an effective option for enhancing acoustic performance in residential and commercial buildings.

While foam insulation, cellulose insulation, and mineral wool insulation can also provide various levels of soundproofing, fiberglass is particularly popular for its cost-effectiveness, availability, and ease of installation. In many building specifications, fiberglass is the go-to choice primarily for its dual role in thermal insulation and sound control.