Thanks for all the testing and feedback. I'm just as baffled by the high frequency noise in your mic -- I've never seen anything like that, but I don't have a t

Thanks for all the testing and feedback. I'm just as baffled by the high frequency noise in your mic -- I've never seen anything like that, but I don't have a ton of extensive tests. Given the even spacing of it, some of it looks to be harmonics? Overall, I'm not really sure how much faith I'd place in noise reduction here. I feel that in general, applying another non-linear process to the signal may just make matters worse. It's hard for me to say since all of the noise I've encountered has been low-frequency ambient/fan noise, which can be easily avoided by just shifting the signal further up. At any rate, the process of cancelling noise for human speech versus modulated tones would look completely different. The hardest obstacles to overcome so far have been non-linear blocks in the receiver, which cause much more distortion than tinny speakers or a mediocre mic.