Comparison of Waveforms of Auditory Middle Responses between Adults and Young Children-Investigation Using Digital Filtering

Abstract

Power spectral analysis and investigation using digital filtration on the auditory middle response (AMR) to tone pip of 1000Hz were performed. The subjects were 13 children aged 1 to 4 years, 13 children aged 5 to 7 years and 9 adults. All of them were proved to have normal hearing.
The dominant: power of Pa ranged in frequency 20-50Hz in adults, and about 20Hz in children. The detectability of Pa was 90-100% by the digital filtering between 20Hz high pass and 50Hz high pass in adults. It was particularly high in 20Hz high pass in children (75% in the group of younger children and 92.3% in the other group) and sharply decreased at 30Hz high pass. The peak Pa and Nb showed a significant increase in latency in children compared with that in adults. The peak Pb was frequently found at 30Hz high pass in adults, but it was hardly detectable by any high pass filtering in children.