Acoustical board is a kind of plate-like material with sound absorption and noise reduction function, which is mainly used in theatres, concert halls, museums, exhibition halls, libraries, studios, recording studios, KTV rooms, bars, industrial workshops, computer rooms, family noise reduction and other places with high requirements for acoustic environment and high-grade decoration. In classrooms, conference rooms or music rooms, we often see sound-absorbing boards installed on the walls in order to isolate the sound and avoid outdoor people being disturbed. There are many small holes on the surface of the sound-absorbing board. After the sound enters the small hole, it will randomly reflect on the inner wall of the structure, which is a bit like a sponge, until most of the energy of the sound wave is consumed and turned into heat energy, thus achieving the effect of sound insulation.