acoustic material; sound-absorbing material
Technical term used in acoustics, construction, and audio engineering for materials that absorb sound.
この部屋の壁には吸音材が使われている。
Acoustic material is used on the walls of this room.
吸音材を天井に取り付けると、反響が減る。
Installing sound-absorbing material on the ceiling reduces reverberation.
Compound of 吸音 (sound absorption) + 材 (material). The exact historical derivation is uncertain, but the components are transparently combined to form a modern technical term.