If you're wondering why your AirPods sound like they're underwater, it's likely because water is trapped in the speaker grille. This can happen if you sweat while wearing them or if you get them wet. While it may not seem like a big deal, water in the speaker grille can distort the sound quality of your AirPods and make them less enjoyable to use. If you're having this problem, there are a few things you can do to fix it.
The first thing you should try is simply drying off your AirPods with a soft, dry cloth. If that doesn't work, you can also use a cotton swab to gently remove any water from the speaker grille. Once you've done that, blow into the grille to help remove any remaining moisture. If your AirPods are still sounding muffled after these steps, try resetting them by putting them back in their case and then holding down the setup button for at least 20 seconds. Finally, if none of these solutions work, it's possible that your AirPods' speakers are damaged and will need to be replaced.