Effect of delayed auditory feedback on stuttering-like disfluencies.

Background: Delayed auditory feedback (DAF) has been used in the treatment of stuttering, providing different results across different populations and age groups.

Aims: This study examines the impact of delayed auditory feedback (DAF) on stuttering-like disfluencies (SLDs) in the spontaneous speech of Jordanian individuals who stutter.

Methods & Procedures: A cross-sectional experimental design was employed to analyse the effects of DAF on the conversational speech of 35 participants (9 females, 26 males) with persistent developmental stuttering, aged 5-29 years (M = 13.1, SD = 6.1). The Stuttering Severity Instrument was used to assess the severity of stuttering. Participants who met the inclusion criteria were asked to talk about general topics of their interests during two different listening conditions (with DAF and without DAF).

Outcomes & Results: No significant DAF effects were found on SLDs in terms of duration [p = 0.18] (blocks, prolongations) and repetition [p = 0.22] (sound repetition, syllable repetition, word repetition). Neither severity nor age affected the use of DAF on SLDs.

Conclusions & Implications: The study concludes that DAF did not result in a significant decrease in SLDs in the spontaneous speech of participants. These findings highlight the limited effect of DAF in reducing stuttering in this specific population.

What This Paper Adds: What is already known on the subject Delayed auditory feedback (DAF) has been shown to reduce stuttering frequency by between 60% and 80%. Furthermore, DAF mediates an immediate improvement in the fluency of speech without affecting speech naturalness (Ritto, Juste, and Andrade, 2015). Van Borsel et al. (2003) concluded that DAF offers an effective tool to reduce stuttering when it is applied as the only treatment outside a clinical environment. They also found that fluency is enhanced when DAF is consistently used over a longer period of time. What this paper adds to existing knowledge This study uses only spontaneous monologue because it was indicated in some previous Arabic studies that the tendency to produce more stuttering in Arabic during oral reading compared to conversational speech may be influenced by a unique, language-specific feature of stuttering in Arabic which is diglossia. (Alshatti, et al., 2022). This means that the coexistence of two varieties of the same language (Modern Standard Arabic versus Dialectical Arabic) could potentially affect the stuttering severity depending on the type of speech sample collected. To remove the impact of the type of speech sample, reading was excluded from the purpose of the current study. What are the potential or actual clinical implications of this work? Nonetheless, the findings of the current study, along with the individual variability of sample sizes in previous studies, support a cautious approach to the use of DAF as a therapeutic intervention for stuttering. In the study of Buzzeti & Oliveira, 2018, the effects were limited to word repetitions. In another study by Stuart et al. (2008), no reduction was found in any of the three measured core behaviours of stuttering (sound prolongations, sound repetitions, and inaudible blocks) during an oral reading task while using the frequency-altered feedback which is similar to DAF.