Sound insulation felt (sometimes referred to as "sound insulation blanket," "damping sound insulation felt," or by the English term "Sound Barrier Sheet") is a thin, flexible material designed to block or impede the transmission of sound. Typically manufactured as a high-density roll, it is composed of materials such as rubber (e.g., butyl rubber), asphalt (modified asphalt), plastics (e.g., EPDM), high-density mineral particles (e.g., barium sulfate), or composites thereof. Its primary function is to block sound waves-particularly structure-borne and solid-borne sound-by adding mass or utilizing a damping effect, rather than by absorbing sound. It is commonly used in conjunction with gypsum board for wall and ceiling sound insulation, as well as for the sound insulation and vibration damping of pipes and mechanical equipment.
Upon hearing the term "sound insulation felt," most people might initially picture something resembling traditional textile felt. In reality, however, sound insulation felt looks completely different; while textile felt is light and soft, sound insulation felt is thin yet heavy.
Common aliases for this material include "sound insulation blanket," "damping sound insulation felt," and "Sound Barrier Sheet." Additionally, while the term "sound insulation felt" may have originated in Japan, similar products in the Japanese construction industry are often referred to as "sound-blocking sheets" (*shaon-sheet*) or "sound-proofing materials" (*bōon-zai*). Its composition generally consists of three parts: a base material (such as asphalt, rubber, or PVC), fillers (such as metal powder or quartz powder to increase density), and additives.