Diffraction - not only will a wave of sound reflect or absorb but it can go over the obstacle. That is why we can hear somebody even with a baffle between.

• 衍射－声音虽然会被反射已经吸收，但是他能绕过阻挡物。这个就是为什么能听到某人在阻挡物后面说哈的声音了。