Why iPhone 7 crashed and mic malfunction

Hello 7malfinction!

Are you helping someone else, or do you need help yourself? It is difficult to discern that from your post.

Assuming it is you that needs help, please see: If the microphones on your iPhone aren't working - Apple Support, about issues with your mic.

If your iPhone is smashed, you can get Product Service and Repair Information - Official Apple Support, by clicking on the link.

I hope this is helpful. Good Luck!