Q: Hello, I have a 6s when i make a call to someone they tell me i sound like im under water or in a closet

Hello denali07,

Thanks for reaching out to the Apple Support Community. I know how important it is to be able to make clear calls from your iPhone, and I'd like to help you isolate and resolve the issue.

Whenever we see an issue with call clarity we want to try to determine the cause. We can start by restarting your phone as normal. If the issue persists, check to see that the microphone is not obstructed by any debris or by a protective case. 

Restart your iPhone, iPad, or iPod touch

If the mic looks clear, I would recommend resetting the Network Settings on your phone. To reset Network Settings, simply tap Settings > General > Reset > Reset Network Settings. Please note, this will remove information such as Wi-Fi networks and passwords, cellular settings and any VPN/APN settings that are on your iPhone. You will need to re-enter this information. 

If those steps do not yield a positive result, you may want to backup and restore your phone. This will help us determine if the issue is tied to hardware or software. These articles will help you backup your data and restore to factory settings.

How to back up your iPhone, iPad, and iPod touch  
Use iTunes on your Mac or PC to restore your iPhone, iPad, or iPod to factory settings  

If you restore to factory settings and the issue is resolved, you can restore using the steps in this article:

Restore your iPhone, iPad, or iPod touch from a backup  

If you run into any trouble or have any other concerns, please reach out again, we're all here to help.

Best Regards