Phoniatrics is the medical research and treatment of organs involved with speech production. In general terms the speech organs means the mouth, throat (larynx), the vocal cords and lungs. Problems treated in phoniatrics include dysfunction of the vocal cords, cancer in the vocal cords or larynx, incapability to control the speech organs properly (speech disorders), and vocal loading related problems.
Speech disorders are intimately related to psychology. Some doctors claim that disorders such as stuttering are entirely psychologycal problems, but that view has recently been mostly discarded. One explanation for stuttering is that there could be a synchronisation problem in the communication between the two halves of the brain have.