[Tarttett]

Will a ferrite bead or toroid do anything to help with noise that is being generated by a computer coming through a ground loop?

 

[PointyFox]

Yes. But not audible noise. Works best for very high frequency stuff. USB soundcards probably won't work. Internal cards can.

 

[Tarttett]

When you say audible noise do you mean a different kind of noise or that the high frequency noise can be too high in volume to be dealt with by the ferrite?

 

[technobear]

The simple answer is 'No'.

 

[Speedskater]

Most ferrites only work on noise above 1 MHz, but ferrite mix 75 & 77 can work above 100 kHz.
Note that high frequency noise can cause IM distortion in the audio band and background noise.