Plane noise overhead

[Quasar44]

You can kind of tell how fast a plane is moving by the time you hear it then see it

If you hear noise but you don’t see it - then it’s moving normal speed. 300-400 mph or so

If you hear it and then immediately see it - it’s moving closer to sound speed

If you just hear the sonic boom before you see the plane then it’s moving so fast that the air gets compressed behind it

 

[Stryder50]

Depends also on the type of airplane, such as jet or prop, and it's altitude.