Individual differences in auditory-motor integration revealed by speech fluency manipulations

A role for auditory feedback in maintaining fluency appears less specific than for pitch control, as one example, but delayed auditory feedback (DAF) clearly provides a potent manipulation of fluency. As most speakers are susceptible to DAF, we predicted DAF is particularly suited to identifying individual differences in auditory-motor integration. We conducted a series of studies to probe susceptibility to DAF-induced disfluency in 60 normally fluent speakers during conversation and oral reading. We further contrasted DAF effects on fluency with dual-task effects on fluency. During conversation and reading under DAF (250 ms delay), multivariate cluster classification indicated speakers show high, low or intermediate susceptibility to disfluency. In contrast, dual-task effects on fluency appeared bimodal with individuals showing high or low susceptibility. DAF susceptibility was not related to dual-task disfluency in 41/60 speakers, but the remaining speakers were disfluent under DAF & dual-task conditions. When the DAF paradigm was extended to adults who stutter, most were classified as highly susceptible. The findings provide compelling evidence that individual differences need to be considered in auditory-motor integration research. Fluency is influenced by both auditory feedback and cognitive factors related to attention, which can inform theories of normal and disordered speech

Obtaining consensus on core components of stuttering intervention for adults: An e-delphi survey with key stakeholders

Background: Evidence-based practice involves the synthesis of multiple forms of evidence to inform clinical decision-making and treatment evaluation. Practice- and patient-based evidence are two forms of evidence that are under-represented in the stuttering literature. The collection of such knowledge is essential to support the design and delivery of effective stuttering interventions for adults.Aims: To build stakeholder consensus on the core components of intervention for adults who stutter, and to establish a guiding framework for the design and development of evidence-based interventions for adults who stutter. Methods & Procedures: Adults who stutter and speech and language therapists (SLTs) with experience in providing stuttering intervention participated in the three-round e-Delphi Survey focused on: (1) identifying key stuttering intervention components, including principles, practices, and structural and contextual elements; and (2) obtaining group consensus on stuttering intervention components. Statements were categorized using the International Classification of Functioning, Disability and Health (ICF) model adapted to the study of stuttering. Outcomes & Results: A total of 48 individuals agreed to participate: 48/48 (100%) completed the Round 1 questionnaire, 40/48 (83%) responded to Round 2 and 36/40 (90%) participated in Round 3. Following content analysis of Round 1, 101 statements were developed, and consensus was achieved on 89 statements perceived as representing the core components of stuttering intervention for adults. Categorization of these statements reflected the key stuttering intervention components relating to personal reactions to stuttering, limitations in life participation and environmental factors Conclusions & Implications: Consensus on the core components of stuttering intervention was reached through engagement with key stakeholders. The evidence-based framework presented highlights the range of key intervention components a clinician should consider when designing interventions for adults who stutte