Headsets with ANR Transmission

Are there any headsets with active noise reduction microphones to make transmissions more clear? Thanks

Active cancellation is not really done in aviation mics. Passive vents, front and back have been the norm for a long time. I tried to help some pilots in the OV-10 with better sound, Ended up putting leather mic muffs on the Lightspeed mics. There is a Calif company (The Boom) that has invented a David Clark replacement element. It does its magic by acoustic shaping. Tested well in the Blackhawks... about $195 each.
But you cannot retrofit many of the common brands the way they mount.
Note that many electret mics have a small gain adjustment screw that is hard to find and adjust. Good luck in your research.

As Flightlogic said, the normal noise-canceling mics (like the excellent DC M7) use a differential electret element that attempts to null the ambient noise mechanically. The talker acts upon the diaphragm differentially to transmit. I use the AeroOregon leather mic muff to provide some overall attenuation of my loud RV cockpit. That helps a lot, plus getting the mic close to your mouth.

concept:

ambient noise
vvvvvvvvvvv
MIC ELEMENT
^^^^^^^^
ambient noise
^^^^^^^^
talker

Active, electronic cancellation is more difficult for a mike than for a headphone. As described above, mikes usually use mechanical cancellation based on direction: the "good" signal (your voice) comes from mostly one direction, while the "bad" signal (noise) frequently comes from all directions. Here's why electronic cancellation is hard: With headphones, the "good" signal is already in electronic form, coming from the radio. The circuit can listen to what's in the headset, electronically subtract the good signal, then send a phase-inverted signal to cancel everything but the good signal. (You might notice that noise, like static, which is already present with the radio signal, will not be cleaned up by this technique.) With the mike, the electronics doesn't have an electrical copy of the good signal, just the good and the bad, combined. Now, having said that, some of the better intercoms/audio panels employ sophisticated signal processing techniques to help clean up the audio coming from the mikes. Do they send the "cleaned up" signal to the radios? I would presume so, but really don't know.