الفهرس 
Auditory evoked potentials (AEPs)
Limitations of obligatory CAEPsOnly 14 pages are availabe for public view
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Abstract
It is well known that a critical period for the acquisition and development of language in children exists. Clinical findings showed that children with hearing impairment who receive appropriate and earlier intervention present better hearing and better language performance than those who start the process at an older age.
The Speech-evoked potentials provide a mean of tapping an individual’s speech processing capacity, who, because of auditory, linguistic, and/or cognitive reasons cannot be reliably assessed using standard behavioral measures. They are also efficient in providing objective data on the benefit of early intervention. According to Sussman et al. (2008), they can be classified as “obligatory” or “discriminative” potentials.
This study aimed to obtain normative data of the speech evoked P1 obligatory cortical auditory evoked potential in eighty children with different age groups. This might suggest the best parameters that can be used for further studies. All children shared in this work were submitted to full history, otological examination, and basic audiological evaluation. Obligatory cortical auditory evoked potentials was studied using Intelligent Hearing System (IHS) SMART Evoked potential, Version 2.39.
A /da/ stimulus was presented on intensity level of 75 dBSPL delivered through loud speaker placed at 45 degree azimuth at the right side of the subject at a distance of 1 meter. The total recording time was 45-60 minutes.
The studied children were divided for analysis purposes into two groups, first group to standardize P1 component in the different age subgroups. This group included a total number of 66 subjects. A Second group was studied to obtain normative data of obligatory CAEPs components and comprised 25 randomly selected subjects.
The result of the first stage of this study revealed that P1 could be easily obtained in normal children (2 month- 18years old). A statistically significant effect of age was detected on both the P1 latency and amplitude. This could be explained based on the maturational process of the central auditory pathway that occurs gradually. It was reflected on the morphology of obligatory cortical auditory evoked potentials, in the form of a decrease of the latency and amplitude value of component P1. While the second stage of this study revealed that the P1 N2 components was the dominant feature of children younger than 7 years and the presence of N1P2 components occurred among subjects > 7 years. This could be explained based on different maturation of different anatomical generators of the four components of the obligatory cortical auditory evoked potentials.
This information, when used cautiously in conjunction with other test results, may provide clinicians with better direction when making decisions about the appropriate intervention for hearing impaired infants and children.