Tinnitus increases with stress. New molds mean a different soundscape and thus more brain capacity needed to decipher it. If your tinnitus increased, then you could also have noticed being a tad more tired in the evening with the new molds. There you have the cause for your tinnitus. It’s not the molds: It’s you!
It’s new, it’s exciting, it’s slightly tiring, too and probably increases tinnitus. Luckely, it won’t stay new. You’ll adapt. If you need the molds, for instance to keep the low frequencies from leaking out, it’ll be worth the investment.
@cvkemp My tinnitus has actually decreased after I started wearing aids. Still noisy if I remove my aids, but it doesn’t keep me awake anymore.
@tim4 The way your own voice sounds, and presumably the general occlusion that you hear can be changed by the audiologist. It’s so common, that e.g. Phonak Target has quick fixes for the complain “own voice sounds to occluded”.
If you’re unsure whether the mold help with understanding speech, go to a challenging situation and test: A place with lots of people talking, like a restaurant, bar or school yard. The little improvements such as custom molds can give you that slight bit of extra understanding that makes the conversation fun instead of work.