The Relationship between Speech Sound Disorder and Cortical Auditory Evoked Potential

Speech sound disorder (SSD) is a speech and language disorder associated with difficulties in motor production, perception, and phonological representation of sounds and speech segments. Since auditory perception has a fundamental role in forming and organizing sound representation for its recognition, studies that evaluate the cortical processing of sounds are required. Thus, the present study aimed to verify the relation between SSD severity measured by the percentage of correct consonants (PCCs) with the cortical auditory evoked potentials (CAEPs) using speech stimulus.

Twenty-nine children with normal hearing participated in this research and were grouped into three groups by SSD level measured by the PCC index. In addition, the groups were subdivided according to the children's age group: between 60-71 months, 72-83 months, and 83-94 months. The CAEP with speech stimulus was carried out in all children.

Older children had longer P1 and N1 latencies. In P2 latency, there was an interference of age only in the severe group. The N2 latency was affected by age, where older children had longer latency.

The amplitude of CAEP has not suffered any interference with the age, or severity of SSD. For the latency, older children generally presented longer averages than younger ones.