The concert hall helps as well, with rigid surfaces that reflect sound waves towards the audience.

音乐厅也有帮助，其坚硬的表面可以将声波反射给观众。

If you have these rigid surfaces, although the friction is the same as the skin, not being able to compress affects the grip and storage of energy, so you get a very weak, or not really a satisfactory, snap.

如果你有这些坚硬的表层，虽然摩擦力与皮肤相同，但不能压缩会影响附着力和能量存储，于是你会打一个非常弱，或者说不是真正令人满意的响指。