Summary

Portable and Clinical Bench models of an automatically triggered auditory feedback masking device, the “Edinburgh Masker”, and their usage are described. The device was found to be effective in abolishing or greatly reducing stammering in 89% of 195 cases. The effectiveness of the portable device has continued in the majority of users during periods of observation of up to three years. In a follow-up study of 67 subjects with six months or more experience of the Masker, 82 % considered it to be of “considerable” or “great” benefit and 67% stated that, as the result of using the device, their unaided speech fluency had improved. No undesirable side-effects have been observed.