If you were traveling in a plane at a supersonic speed would you hear the engines?

Answer 1

Yes

When a plane goes through the sound barrier, it produces a wake like a boat going through water. The wake(or waves) propagate out from behind the plane in a cone. Any observer outside this cone does not hear the plane until the shock cone reaches him.

If you are a passenger on the plane, then you are traveling the same speed so the sound waves will reach you easily.

It is like the illustration of a Fly inside a plane. The Fly can still fly from the back of the plane to the front but he is not going supersonic. He would appear to be going supersonic to someone on the ground.

ALso, read the observations of the Astronauts. Their space shuttle reaches Mach 2 or 3 before engine separation and I'm sure they will describe the change in sound.

ALTERNATE QUESTION:Do you hear your rockets if you are in Space? There is no atmosphere in space so sound can not travel. However, there is atmosphere inside the rocket so they do hear the vibration.

Answer 2

No, if you were traveling in a plane at supersonic speed, you would not hear the engines because the sound waves created by the engines cannot catch up to the plane moving faster than the speed of sound. This creates a "sound barrier" where the sound waves cannot propagate effectively.