What is the ruling on listening to the answers that teachers give to students during exams, knowing that not listening may lead to the success of other undeserving students? And am I sinful for answering the oral Quran exam with something that is not entirely correct?

The student in such a situation is not commanded to cover his ears. However, he is required not to intentionally cheat. What is conveyed to his hearing without seeking or searching for it, it might be permissible to benefit from it, but this is a matter of doubt and hesitation.

The more scrupulous approach is to occupy oneself or not focus on whoever is dictating the answer to the students. However, we do not assert that this is obligatory, nor do we rule that a person who listens and benefits is sinful.

The responsibility for cheating lies with the school and the teachers who administer the exams to the students, not with the student himself who answers what he is asked about.