Henschen T L, Burton N G
Biofeedback Self Regul. 1978 Mar;3(1):91-6. doi: 10.1007/BF00998566.
Two middle-aged subjects, a male and female, with spastic dysphonia (hoarseness, stammering) were treated with both frontalis and throat muscle electromyographic (EMG) biofeedback. Both subjects reported no noticeable improvement in their voice qualities. Results of a battery of psychological tests provided some insight into the inability of EMG treatment, as well as other therapeutic approaches, to alleviate the pathology.