The instructors should work hard to let them produce at least one basic sound.
Problem 2 is about the people who murmur in the mouth. You have to be attentive to these people.
This problem is seen among those people who have practiced in their own style believing any sound produced to be the esophageal speech. In the course of time, they will realize by themselves that it is not correct esophageal speech. However, if the speech is left uncorrected, the result is that they will lose confidence and become drop-outs, as they cannot make correct pronunciation. Immediate correction is indispensable, and correction is possible.
a) How to find them
They produce characteristic sounds, so you can recognize them by listening to their speech.
