Delayed Auditory Feedback Research Paper

Journal of Fluency Disorders 27 (2002) 187–201

The effect of fast speech rate on stuttering frequency during delayed auditory feedback
Garen Sparks a,∗ , Dorothy E. Grant a , Kathleen Millay a , Delaina Walker-Batson a , Linda S. Hynan b b Department of Communication Sciences and Disorders, Texas Woman’s University, Dallas, TX, USA Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA Received 26 June 2000; received in revised form 1 October 2001; accepted 14 March 2002

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Abstract Delayed auditory feedback (DAF) has been documented to improve fluency in those who stutter. The increased fluency has been attributed to the slowed speech rate induced by DAF, but recent experiments have suggested
None of the subjects reported having had any experience with DAF during speech therapy. All of the subjects passed a bilateral hearing screening test and showed sensitivity equal to or better than 20 dB HL for the frequencies of 250, 500, 1000, 2000, 4000, and 8000 Hz (ASHA, 1990). They also had normal middle ear function bilaterally according to impedance screening (ANSI, 1989). Standard American English was the first language of each participant. Subject B reported that he was initially diagnosed with attention deficit hyperactive disorder at 7 years of age and was rediagnosed with attention deficit disorder at 18 years of age. Subject C’s conversational speech included characteristics of Black English. No other subject had any additional speech, language, or neurological differences. 2.2. Materials All testing and data collection were conducted in one side of a double-walled, sound-treated, audiometric test suite. The DAF conditions (55, 80, and 105 ms delays) were created by a Phonic Mirror mini DAF (Model PM 505) and the gain was arbitrarily set at 20 dB for each subject. A microphone for the DAF (Phonic Ear AT164-l omni-directional lapel microphone) was attached to the subjects’ clothing approximately 4–6 in. below the chin. All the subjects’ speech samples were video and audio recorded with a camera (Panasonic VHS Reporter AG-185 on a Bogen tripod Model 3126) and audio
Fast oral reading rate decreased for the severe stutterers from 5.5 syllables/s in the 55 ms DAF condition to 5.1 syllables/s in the 80 and 105 ms DAF conditions. Stuttering episodes remained fairly low for the mild stutterers under no DAF while reading at their normal rates. A mean of 1.3 stuttering episodes was found for the no DAF conditions and means of 0.5, 0.9, and 0.9 stuttering episodes were found for 55, 80, and 105 ms DAF, respectively. Stuttering episodes during normal reading rates decreased for the severe stutterers from a mean of 15.2 stuttering episodes in the no DAF condition to means of 1.2, 1.0, and 1.0 stuttering episodes in the 55, 80, and 105 ms DAF conditions, respectively. The number of stuttering episodes decreased slightly for the mild stutterers reading at their fast rates from the no DAF to the DAF conditions. An average