I would say it seems likely there's a sort of novelty effect associated with something like wearing a mask. But at the same time, I'd say this doesn't imply wearing a mask will always be a help, and will remain so over time. Also, since you're sharing, I'd like to point out that being covert is in itself an issue you should be addressing. The less you feel like you have to hide, the more comfortable your everyday life will become. That's something you can work on (even without going to see a speech therapist).