What is this opening for?

have a 2020 MBP 13 (A2251) While replacing the touch bar, found the mic hole under it just above the 2 key. The hole is closed up by the touch bar's sticky tape so was curious what this is for?

For keyboard noise cancellation? Tried photobooth video while tapping on the keyboard and can hear it (does the same on my Macbook Pro M1 with the same touch bar+mic design)

Anyway, like to test this mic since I replaced the touch bar but not sure how. I did clean out the hole but not poke down really far to avoid damaging the mic (didn't peel it off to avoid breaking any seals)