For anyone that is confused and thinks that the second hole on top is a second microphone, no it's a hole to test water resistance and help with the pressure inside phone. I've literally asked that the Samsung employee when I was in a Samsung Korea factory. S23, Flip/Fold 5 too.
Fyi in the user guide, it just says, air hole.
No, I've literally asked the factory manager in Korea last summer. I wish Samsung stated that clearly. Everybody things that it's a second mic which makes no sense. 
