I don't think it will be possible to make wireless earbuds or a ring with replaceable batteries without seriously compromising the ergonomics of fitting onto or into the human body.
I have a pair of earbuds designed to be as diminutive for sleeping comfortably and I have no idea how you would do that with a replaceable battery even if Airpod sized devices can be done.
I have a pair of earbuds designed to be as diminutive for sleeping comfortably and I have no idea how you would do that with a replaceable battery even if Airpod sized devices can be done.