Unfortunately I don't think there is a lot you can do. I don't know of any software workaround.
The mic is doing what it is designed for. You could turn the speaker volume down, but in all honesty if you turned it low enough for the mic not to pick it up then I doubt you would hear it either.
What is needed is a noise cancelling mic, one where the sensitivity is adjustable. Then is is a case of balancing the speaker volume and mic sensitivity.