Background: While recording the Brainstem Auditory Evoked Potential (BAEP) wave forms (I-V), the peak latency value of each BAEP wave forms at lower stimulus intensity rates are quite small since by increasing the stimulus rates those differences which are not accessible at lower rate will appear at higher stimulus rates. Age and sex are the factors that affect the Brainstem Auditory Evoked Potential responses. The stimulus rate is the other factor that may have a noticeable affect on I and V peak latency and their differences (I-V) changes which have been verified in this study.

Materials and methods: In present study, the BAEP wave forms I and V were recorded according to the 10-20 system and by presenting the stimulus rates of 5pps, 10pps, 20pps, 50pps and 100pps on ipsi lateral ears of 63 normal adult subjects while the time occurrence (peak latency) of waves I and V and their differences (I-V) in different age and sex groups were compared statistically.

Results: By presenting the stimulus rates of 5pps, 10pps, 20pps, 50pps and 100pps on ipsi lateral ears of all subjects in 63 normal adult subjects in different age and sex groups, females had smaller peak latencies and inter peak latencies values in waves I and V than males. By increasing the stimulus rates from 5pps to 100pps, peak latencies and inter peak latencies value of all BAEPs waves that recorded from different age groups of both sex were also increased. The variations in peak latencies values of waves I and V in youngest compare to oldest age groups in all stimulus rates were larger while the values in 50pps were prominent.

 Conclusion: The results of this study showed that an increase in stimulus intensity rates will increase the peak latencies and inter peak latencies values in waves I and V in different age and sex groups.