Headsets with boom microphones (specifically) capture virtually no ambient noise because the gain on the microphone is extremely low (the relative volume of you

Headsets with boom microphones (specifically) capture virtually no ambient noise because the gain on the microphone is extremely low (the relative volume of your voice picked up 1 inch from your mouth is much higher than that of anything else at the same location). I can vacuum my house while on my bluetooth headset and people won't hear it on the other end.