当声音(声波)入射到物体的表面时,有一部分声音会被反射回去。如在空旷的大礼堂里,我们若大喊一声(原声),经墙壁反射后,就会听着一个或几个同样的声音在回荡,若在深山峡谷里这种现象会更加明显。这种现象就叫回声,也称为声音的反射。 When the sound (sound wave) is incident on the surface of the object, part of the sound is reflected back. In an empty auditorium, if we shout loudly (acoustic sounds) and we reflect through the walls, we will hear one or more of the same voices reverberating. This phenomenon will be more pronounced in deep mountain valleys. This phenomenon is called echo, also known as the reflection of sound.