Verbal dichotic listening in developmental stuttering: subgroups with atypical auditory processing

Area of Science:

• Neuroscience
• Speech and Hearing Science
• Psycholinguistics

Background:

• Stuttering is hypothesized to involve aberrant hemispheric dominance.
• Auditory processing deficits are observed in some adults who stutter.
• Dichotic listening has not been extensively studied in relation to handedness and stuttering.

Purpose of the Study:

• To investigate auditory processing and laterality in adults with persistent developmental stuttering.
• To examine sex and handedness differences in auditory processing among individuals who stutter.
• To explore the relationship between handedness and dichotic listening measures in stuttering.

Main Methods:

• Dichotic listening tests with consonant-vowel stimuli were administered to adults with persistent developmental stuttering (n=18) and controls (n=28).
• Three attention conditions were used: nondirected, right-directed, and left-directed attention.
• Auditory laterality was assessed by ear advantage and lateralization shift magnitude, considering sex and handedness.

Main Results:

• Right-handed men who stutter and controls showed a right-ear advantage (REA).
• Left-handed men who stutter exhibited a left-ear advantage (LEA), suggesting atypical auditory processing.
• Right-handed women who stutter displayed no ear bias and had difficulty with attentional shifts, indicating potential attentional deficits.

Conclusions:

• Left-handed men who stutter and right-handed women who stutter demonstrate atypical auditory processing, with distinct patterns.
• The findings suggest mixed dominance in left-handed men who stutter and attentional deficits in right-handed women who stutter.
• Aberrant hemispheric dominance alone does not explain stuttering, and further research is needed, especially regarding left-handed women.