It would be very spooky if he learns about her secret on the spookist week of this month!
Also if I understood this correctly, he wants to be trustworthy for her to share her secret with him. But he feels unworthy for how pathetic he feels from worrying about his voice?
Does this mean he will no longer shy away from using his voice or just stop worrying about having such high pitched voice?
Either way, I respect how they are not just making him being all fessy about his own anxiety, and tying it up to him wanting to be worthy for Happiness.