It’s difficult to learn how to pronounce a word when you can’t hear the sounds clearly. Dictations are almost impossible to get right. All communication suffers.
Often this is not a hearing problem. It can just as well be a listening problem causing speech and language delays. It can even make a child non-verbal.
Dr Tomatis demonstrated that his method immediately improved speech and voice quality to the French Academy of Medicine in 1959.
The Academy members could hear the instant change. To get lasting improvements, however, you need to do a full Tomatis® programme.