i spoke to a speech pathologist a while back and the way she described it was all these speaking actions are in different loops in the mind. for instance speaking to someone is actually very different to reading out loud or singing. most people don’t stutter on their own even if they read outloud. and a lot of people don’t stutter while singing (a lot of speech techniques have a singsong rhythm). everyone stutters differently but i hope this clarifies alittle?