Reflection of Waves

Plane Wave Reflection

平面波反射

"The angle of incidence is equal to the angle of reflection" is one way of stating the law of reflection for light in a plane mirror.

光在平面镜中的反射定律可以表述为入射角等于反射角。

Sound obeys the same law of reflection .

声音遵循相同的反射定律。

Point source of sound reflecting from a plane surface

点声源在平面表面反射

When sound waves from a point source strike a plane wall, they produce reflected spherical wavefronts as if there were an "image" of the sound source at the same distance on the other side of the wall.

当点声源发出的声波撞击平面墙时，它们会产生反射的球面波前，就像声源在墙的另一边同样距离处有一个‘像’。

If something obstructs the direct sound from the source from reaching your ear, then it may sound as if the entire sound is coming from the position of the "image" behind the wall. This kind of sound imaging follows the same law of reflection as your image in a plane mirror.

如果某物阻挡了声源直接发出的声音到达你的耳朵，那么声音可能会听起来像是从墙后‘像点’的位置发出的。这种声音成像遵循与平面镜中你的影像相同的反射定律。

Reflection from Concave Surface

从凹面反射

Any concave surface will tend to focus the sound waves which reflect from it. This is generally undesirable in auditorium acoustics because it produces a "hot spot" and takes sound energy away from surrounding areas. Even dispersion of sound is desirable in auditorium design, and a surface which spreads sound is preferable to one which focuses it.

任何凹面都会倾向于聚焦从其反射的声波。这在音乐厅声学中通常是不希望的，因为它会产生一个‘热点’，并将声能从周围区域带走。即使声波的扩散在音乐厅设计中也是可取的，一个能扩散声波的表面比一个能聚焦声波的表面更可取。