Response strength and latencies of auditory steady-state responses from age six.

OBJECTIVE

Auditory-steady state responses (ASSRs) to stimuli modulated by different frequencies may differ between children and adults. These differences in response characteristics or latency may reflect developmental changes. This study investigates age-related differences in response strength, latencies, and hemispheric laterality indices of ASSRs for different modulation frequencies.

DESIGN

Multi-channel EEG was used to measure ASSRs to broadband noise, modulated at either 40 or 80 Hz, presented at 70 dB SPL to the left, right, or both ears.

STUDY SAMPLE

This study involved 18 adults (20-26 years) and 17 children divided into two age groups: younger children (6-10 years) and older children (11-14 years).

RESULTS

Advancing age was associated with increased response strength and prolonged latencies for 40-Hz ASSRs, with significant differences observed between adults and younger children. No significant age-related differences were noted for 80-Hz ASSRs. Laterality analysis indicated a right-hemisphere tendency for 40-Hz ASSRs in older children and 80-Hz ASSRs in younger children, respectively.

CONCLUSION

The study indicates the development of 40-Hz ASSRs with increasing response strength and prolonged latencies. The results of children with normal hearing are important for further research on children with hearing impairment.