Effectiveness of a behind-the-ear device delivering delayed auditory feedback on stuttering in the daily life of an adult stutterer

Abstract

It is well known that most people who stutter show an immediate reduction in stuttering when they speak under a condition of altered auditory feedback (AAF). Although delayed auditory feedback (DAF), a type of AAF, has been used in several therapy programs, its effectiveness is reportedly difficult to transfer to daily life. Today, several types of body-worn battery-powered DAF devices have been developed that enable people who stutter to use them in their daily life. However, there are few reports assessing their effectiveness based on objective observation under daily speech situations. We had an adult stutterer wear a DAF device when she made phone calls during a period of four months in order to assess its effectiveness on her daily speech. The findings showed a reduction in both her speech rate and frequency of disfluency in speech during phone calls. She felt her speech improved in naturalness and in reduction of avoidance. The reduction in the frequency of disfluency carried over after the four months of usage. In this way, the effectiveness of the DAF device on stuttering was demonstrated by objective data under a daily speech situation.