My Right Airpod is quieter than left.

This has happened to me like 10 times till this point usually alternating airpods what you can do is walk into apple and as long as your still under warranty and they havent been heavily cosmetically damaged you’ll get them replaced.

If you have expensive AirPods, I would give them to a specialist to solve this problem. If not, I would buy new ones. This is why I buy inexpensive devices because I know that they often break down. After I broke an expensive phone without being able to fix it, I decided that I won't spend a lot of money on devices. And I can say that I bought fake AirPods (here you can see the review https://woahtech.com/best-fake-airpods/) and am pleased with their price and quality. So I use them mainly to listen to music on the bus/train or when I run in the morning. Due to the fact that they have excellent noise insulation, my brain is resting from the noise and bustle of the city. I turn on Chopin music and run along the ocean coast, it creates a sense of comfort and relaxation.

these are not good answers.

I know the thread is old.

Over the summer, I had a pair of AP2 and I took them back from my daughter because she upgraded to AP Pros. One day I started using them and one earbud was muffled and the sound was low. I thought that was odd because there is no visual damage of it. It still charges and holds a charge. I tried all of the tricks including cleaning, adjusting the sound, etc.... and nothing seemed to fix it.

A month or two ago, I took them to Apple and the guy ran a diagnostic test and told me there is something wrong with both earbuds. He didn't go into detail of the problem but the case is fine.

The conclusion was I had to replace them with new ones. I still don't know what happen to them. My daughter could have dropped them for all I know.