A drum head is broken down into a head body, which in turn is broken down
into a solid portion and an accumulating portion, and a rigid base plate;
the solid portion offers a beaten surface to a drummer, and the
accumulating portion or an array of pillars and the base plate form in
combination a locally vibratory portion; when a drummer strikes the
beaten surface with a stick, the solid portion caves in for accumulating
a part of the impact load, and gives rise to resilient deformation of the
pillars beneath the cave so that another part of the impact load is
accumulated in the deformed pillars as the elastic strain energy; the
elastic strain energy is released through the local vibrations of the
pillars, and the vibration energy is transmitted to a small amount of the
air therearound so that the noise is faint.