bluetooth headsets (clip-on type), ambient noise
 

I'd like to ask if anyone has used a bluetooth headset receiver (Nokia BH-214, Sony MW600, DRCBT15, etc) along with an inline microphone. Most one of these receivers have a built in mic. It's not clear if any can switch over to using one that's built into the headset (via 4-ring TRRS plug), such as on the stock WH-205.

The reason I ask is that the N900 mic picks up a lot of background noise. I am frequently told this when I'm on normal calls, and the phone is nearly useless in the noisy data center where I work. A clip type microphone at neck or chest level won't work.

I've found that a boom headset that I like (Plantronics 480), and works pretty well in that environment. The question is, how can I access that microphone over BT?