What the HECK is that SOUND!?!?

[JFox]

Hey guys,

Been a minute. I've been working hard and such, you know. Just rolled over 11000 miles on the 'ol FR-S.

It seems to have developed a "humming" or "rubbing" sound that is intermittent and independent/not related of/to engine RPM. Nor is it affected by the car being in/out of gear (manual transmission).

If I had to describe it in one word I'd say it's like a "howl" that will come on for about 2-5 seconds at random times. Honestly, it's eerily similar to the sound my old Geo PRIZM made when the wheel bearing went.

It does not, however, increase/decrease based on speed of vehicle or whether it's in a turn or not. I can faintly feel a vibration in the pedals, almost like it's resonating.

Another way I might describe the sound is someone trying to play a trumpet or trombone for the first time - where air and just the slightest note comes through - it sounds like that little bit of a note.

I might try to get video/sound clip but honestly it's not very loud, and would likely get drowned out by the road noise/ambient noise.

Any ideas guys? I'm at a loss here.