why does the noise from a plane in the sky happen suddenly?

Question

Noticed it today, rather than a gradual build up of noise you just suddenly hear an airplane like it appeared out of nowhere?

In: Physics

Answer 1

You’re floating on the lake. A boat goes past you, really fast. A few seconds later, the wake from the boat hits you, makes you bob up and down a good bit. The airplane is the boat. The sound is the wake.