This page is just a beginning. I ask for more contributions.
Squeaks can come from several sources. A badly balanced reed can do it. But usually for a new student or an adult relearning, it would be
1. not holding the reed firmly enough,
2. putting too much reed in the mouth,
3. not making the subconscious adjustments in the throat that all players make after they are used to playing. (The throat moves almost like when singing.)
4. Fingers not closing the holes properly.