I've had my Surface Pro since 2017, after returning my original unit for a failed hard disk I noticed an odd mic static from the replacement unit. Unfortunately, I noticed this months after getting the replacement when my work transitioned from phone to computer based teleconferencing so I doubt Microsoft will do anything to remedy this. My intimidate solution was to use a USB microphone (Blue Snowball) attached to my dock and a Bluetooth headset when traveling but this comes with its own inconveniences. I've attached a GIF of the EQ's on the sound setting page and this is a link to an MP3 of the sound as its being recorded (I start talking at about 8 seconds). Thanks in advance, any help would be appreciated!