What is this sound on the Shuttle?

[Keatah]

What is this sound on the shuttle? It sounds like a mix of a turbine spooling and some sort of howling.. Is this machinery or wind noise? It begins at about 3:52 and continues till about 4:48 where it just fades away.

 

[Urwumpe]

Thats one of the vibration modes caused by aerodynamic forces, it fades away after passing Max-Q, which is one of the loudest events during launch.

 

[MattBaker]

Probably the atmosphere, that should be the phase of the launch were they actually reduce thrust because the atmospheric pressure is too high. Also I think because of the pitch of the shuttle the aerodynamics become worse than if it would lift off straigt up, so more disturbance by the atmosphere