A study conducted by Isabela Crivellaro Gonçalves et al. suggests that children who stutter present differences in neural processes related to the processing of acoustic information, when compared to typically developing children, especially when more complex stimuli, such as speech, is considered. The fluency-disabled population is heterogeneous, suggesting that this disorder results from multiple interacting physiological processes reflecting more than one underlying cause. Current scientific evidence supports the hypothesis that people who stutter have anomalous connections in auditory regions of the left hemisphere, related to the sensory feedback of speech sounds.
The most widely used AEP in clinical practice is the auditory brainstem response (ABR). ABRs can be recorded using different stimuli and, although the click stimulus is the most frequently used, additional methods involving speech stimuli have been developed. Speech-evoked ABRs can be used to examine the neural basis of the auditory function due to its remarkably faithful representation of the stimulus’ acoustics. Gonçalves et al. conducted the experiment on 20 native Brazilian-Portuguese speaking children (14 boys and six girls), with ages ranging from seven to 11 years, divided into two groups: G1 – 10 children who stuttered (CWS – mean age 10.1 years); G2 – 10 children who did not stutter (CWNS – mean age 10.3 years). Auditory Brainstem Responses (ABR) using stimuli of different complexities were recorded in order to investigate possible neural synchrony deficits in children who stutter (CWS).
CWS showed greater variability in latency values, as well as a statistical trend towards significance regarding differences between right and left ears for the interpeak I-III in the click-evoked ABR. In the speech-evoked ABR, the latency values of wave C and the amplitude of VA complex were significantly higher in CWS.
Further future research using different AEP are needed to support the study of speech processing at different levels of the central auditory nervous system in stutterers, which will provide relevant and objective information about possible “subclinical” abnormalities related to the speech perception and processing in these individuals. It will also allow a better assessment of the benefits and limitations of using stimuli with different complexities in the electrophysiological evaluation of people who stutter.