Mine have been doing this for months now - it is only the left earbud and it drives me INSANE. Every time I move I hear the swoosh tone. I happened to be looking at the app one day when it was doing this and noticed that the ambient sound was going on and off. I seriously can not take it any more. This is my second pair (I had the first gen) and I love them, but I can't go on like this. I've been looking at other models and brands because nothing I do seems to fix this issue. I've reset a million times. This is really unfortunate.
Did you turn on the ambient sound mode on your earbuds? Could you please provide me your full model number?
I'm having the exact same problem. The right earbud's volume is attenuated significantly. Also, when I open my mouth to yawn or move my head side to side, I get the "WOONG" sound. Frustrated with these earbuds.