Clinical Application of Auditory Steady-State Response evoked by multiple simultaneous amplitude-modulated stimuli (amplitude-modulation following response : AMFR) for Assessment of hearing in infants and young children

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 13671765
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Yamagata-uniersity
• Principal Investigator: WATANABE Tomoo Yamagata-University, Scholl of medicine, Assistant professor, 医学部, 助手 (60344793)
• Co-Investigator(Kenkyū-buntansha): ITOU Tsukasa Yamagata-University, School of medicine, assistant professor, 医学部, 助手 ; SUZUKI Yutaka Yamagata-University, School of medicine, assistant professor, 医学部, 助手 (70250925) ; AOYAGI Masaru Yamagata-University, School of medicine, Professor, 医学部, 教授 (40107181)
• Project Period (FY): 2001 – 2002
• Keywords: steady-state response / amplitude-modulation following response / multiple amplitude-modulated tones / 他覚的聴力検査装置

Research Abstract

In recent years newborn hearing screening has been widely implemented using automated ABR screener and EOAE test unit. However, hearing threshold prediction and follow-up evaluation using traditional ABR technique cannot provide sufficient information in a frequency-specific manner. Thus, it is necessary to develop new tests to obtain detailed information from specific cochlear regions. Our study is indicated about new detection algorithm to use multiple simultaneous amplitude-modulated stimuli and separate analysis for each MF with phase coherence. The responses for each MF are separated with software-triggering from the averaged waveforms to obtain using simultaneously multiple amplitude-modulated tones, from which the phase coherence value is calculated for each MF. Test reliability of SSR using simultaneously multiple amplitude-modulated stimuli (Four-CF combined stimulus in MFs around 40 HZ) with our detection algorithm was evaluated among normal-hearing adults and comparison with resulting in mono AM tone was performed. In addition examples of puretone audiograms and thresholds estimated from SSR using simultaneously multiple ampliude-modulated stimuli were demonstrated in adult subjects with hearing impairment. The new algorithm for response detection of SSR using simultaneously multiple amplitude-modulated stimuli at the optimal modulation rates is expected in clinical use for assessment of hearing in infants and young children.