Auditory feedback control in adults who stutter during metronome-paced speech I. Timing Perturbation.

The study included 15 adults who stutter and 16 adults who do not stutter, and it tested a laboratory speech task. Stuttering was infrequent in the experiment: 6 out of 15 adults who stutter produced no stuttering disfluencies. One adult who stutter had an SSI-4 score below the lowest percentile but was kept in the stuttering group based on self-report and day-to-day variability in scores. The target sentence was repeated almost 200 times throughout the experiment, and the authors note that repeated reading can reduce stuttering, although they did not see a clear adaptation pattern. The feedback system had a global delay of about 32 ms, which can affect speech in people who stutter and may have influenced the results. The perturbation magnitude was not perfectly controlled and was smaller in the metronome condition than in the normal condition. One participant completed 200 trials instead of 240 because of a technical error. Participants were native American English speakers with normal hearing and no other speech, language, or hearing disorders, so the results may not extend to other populations.

The authors declared no competing interests.

Do not read the 1.2% versus 7.4% stuttering reduction as evidence that metronome pacing treats stuttering by correcting auditory timing control. The study was a short laboratory task in 15 adults who stutter, and the timing perturbation response did not differ between adults who stutter and adults who do not stutter.