A phenomenon which can occur any time there is any type of wave, which amounts to two waves canceling each other out. If two different waves meet at the same place, and one would hit its peak while the other would hit its trough, the waves will cancel, and there will be no disturbance. Alternatively, if both waves would hit their peaks at the same time, the waves will boost each other, so that there is a greater disturbance.
Come, you lost Atoms, to your Centre draw,
And be the Eternal Mirror that you saw:
Rays that have wander'd into Darkness wide,
Return and back into your Sun subside.
From Farid al-Din Attar's
The Conference of the Birds