Auditory Evoked Potential. Speech Perception. Electrophysiology.

The examination of cortical auditory evoked potentials is used to characterize auditory processing, based on different stimuli, which can be elicited by pure tone or speech. Speech sounds are composed of different distinctive features that are defined as acoustic-articulation characteristics capable of marking the difference between phonemes. Changes in speech sounds, a condition frequently observed during child development, may be related to difficulties in auditory discrimination. Considering the characteristics of speech for the definition of stimuli that can be used to elicit evoked potentials, this research was divided into three stages. Initially, speech stimuli were defined considering the distinctive features to perform the examination of cortical auditory evoked potentials in adults and children with normal hearing and speech, with the aim of developing a diagnostic test to identify levels of auditory discrimination. Preliminary results showed that the stimuli were able to generate cortical auditory evoked potentials, making it possible to identify the N1-P2-N2 complex in adults and children. The analysis of partial data showed that there is no difference between the three stimuli in the adult population. Data collection from children has not been completed. Then, a systematic review was carried out with meta-analysis on cortical auditory potentials in children with phonological disorder, finding that there is no difference in N1-P2-N2 latency in these children, when compared to children with typical speech development. Finally, a speech screening application is under development with the aim of early identification of children with phonological disorders. Initial tests indicate that the application works properly.