I am noticing the horrible smell as well. It also gives me a headache and to me is a strong chemical smell similar to acetone or some other solvent that is off-gassing. .
I purchased my Airpods Pros in January and I noticed a faint smell similar to blueberries but it wasn't that bad. Then I started to use the Airpod Pros for a few hours on the weekends and the smell became stronger each time I used them. I'm assuming that my body heat intensified the off-gassing and when I removed the earpieces the smell lingered for a long time in my ears. I would have to wash my ears with soap to help remove the smell.
Initially I believed that the smell came from the case because when I sniffed the case the smell was awful. I assumed that the silicone on the ear tips absorbed the smell from the case. I contacted Apple Support on Feb. 26 told them about the problem and they suggested that I bring in my Airpods Pros to the local Apple Store with the original packaging and they would order an exchange.
Last night I picked up the new exchanged Airpods Pros and gave the store my old ones. They gave the new ones to me in three separate boxes: 1) empty case; 2) left earpiece with silicone tip; 3) right earpiece with silicone tip. Each was packaged separately. I sniffed the case in the store and didn't smell anything - no obnoxious smell. Then as we unpacked each earpiece I sniffed them and they had that same faint smell of blueberries. Not obnoxious but it was the same smell I noticed with the first pair. The apple store employee also gave me to small packages with additional silicone eartips.
When I arrived home I put each earpieces inside the charging case and then left them to charge overnight. When I checked them in the morning the tips had a stronger pungent smell and the case had a mild similar smell. I decided to remove the earpieces from the charging case and just set them out for the day to air out. I also left the charging case still plugged in but with the lid held open with a little tape. Before I left for work I decided to sniff the additional silicone eartips that were never put in the case and were packaged separately. They had the same obnoxious smell! I then went to my original packaging from the first pair of Airpods Pros and pulled out the unused eartips in the box. These have never been in the case and they also had the same horrible smell.
I want to emphasize that the replacement airpod pro case and earpieces have not been worn yet. They were charged together overnight but not worn. The smell is strongest from the silicone tips even from the extra sizes of tips that haven't even been in the charging case and were packaged separately.
I am growing more and more convinced that the obnoxious smell is coming from the silicone tips and not from the case.
I am not sure there is any fix for this. I believe Apple needs to either find another supplier or make the eartips out of another material. I'm afraid I will also have to return my replacement Airpod Pros because I am convinced they are offgassing something that isn't healthy.
I will update all of you If the smell goes away after airing them out all day or longer. I'm just not hopeful at this point.
