The title may sound a bit confusing, but basically, if it's raining outside, and you're in an interior, and you put on, say, the Eyebrella, the "pitter-patter" sound of rain on the hat will still play, despite the fact that you're indoors.
Steps to Reproduce
Wear a hat indoors that produces ambient noise based on outdoor occurrences.
Wear a hat indoors that produces ambient noise based on outdoor occurrences.
A developer has marked this issue as fixed. This means that the issue has been addressed in the current development build and will likely be in the next update.