A portable visual-feedback device for reducing excessive vocal loudness in persons with mental retardation.

A simple portable device was employed to reduce excessive vocal loudness in two adults who functioned within the moderate mental retardation range (one in the lower and one in the upper half). The device provided these adults visual feedback when the voice exceeded a preset level of loudness. Data showed that the device was useful in helping both adults reduce excessive vocal loudness across different daily situations. Characteristics and applicability of the device are discussed.