Acoustic Change Complex Evoked by Horizontal Sound Location Change in Young Adults With Normal Hearing

Zhi-Tong Fan; Zi-Hui Zhao; Mridula Sharma; Joaquin T Valderrama; Qian-Jie Fu; Jia-Xing Liu; Xin Fu; Huan Li; Xue-Lei Zhao; Xin-Yu Guo; Luo-Yi Fu; Ning-Yu Wang; Juan Zhang

doi:10.3389/fnins.2022.908989

Acoustic Change Complex Evoked by Horizontal Sound Location Change in Young Adults With Normal Hearing

Front Neurosci. 2022 Jun 6:16:908989. doi: 10.3389/fnins.2022.908989. eCollection 2022.

Authors

Zhi-Tong Fan¹, Zi-Hui Zhao¹, Mridula Sharma², Joaquin T Valderrama^{2

3}, Qian-Jie Fu⁴, Jia-Xing Liu¹, Xin Fu¹, Huan Li¹, Xue-Lei Zhao¹, Xin-Yu Guo¹, Luo-Yi Fu¹, Ning-Yu Wang¹, Juan Zhang¹

Affiliations

¹ Department of Otolaryngology Head and Neck Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
² Department of Linguistics, Faculty of Human Sciences, Macquarie University, Sydney, NSW, Australia.
³ National Acoustic Laboratories, Sydney, NSW, Australia.
⁴ Department of Head and Neck Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.

Abstract

Acoustic change complex (ACC) is a cortical auditory-evoked potential induced by a change of continuous sound stimulation. This study aimed to explore: (1) whether the change of horizontal sound location can elicit ACC; (2) the relationship between the change of sound location and the amplitude or latency of ACC; (3) the relationship between the behavioral measure of localization, minimum audible angle (MAA), and ACC. A total of 36 normal-hearing adults participated in this study. A 180° horizontal arc-shaped bracket with a 1.2 m radius was set in a sound field where participants sat at the center. MAA was measured in a two-alternative forced-choice setting. The objective electroencephalography recording of ACC was conducted with the location changed at four sets of positions, ±45°, ±15°, ±5°, and ±2°. The test stimulus was a 125-6,000 Hz broadband noise of 1 s at 60 ± 2 dB SPL with a 2 s interval. The N1'-P2' amplitudes, N1' latencies, and P2' latencies of ACC under four positions were evaluated. The influence of electrode sites and the direction of sound position change on ACC waveform was analyzed with analysis of variance. Results suggested that (1) ACC can be elicited successfully by changing the horizontal sound location position. The elicitation rate of ACC increased with the increase of location change. (2) N1'-P2' amplitude increased and N1' and P2' latencies decreased as the change of sound location increased. The effects of test angles on N1'-P2' amplitude [F(1.91,238.1) = 97.172, p < 0.001], N1' latency [F(1.78,221.90) = 96.96, p < 0.001], and P2' latency [F(1.87,233.11) = 79.97, p < 0.001] showed a statistical significance. (3) The direction of sound location change had no significant effect on any of the ACC peak amplitudes or latencies. (4) Sound location discrimination threshold by the ACC test (97.0% elicitation rate at ±5°) was higher than MAA threshold (2.08 ± 0.5°). The current study results show that though the ACC thresholds are higher than the behavioral thresholds on MAA task, ACC can be used as an objective method to evaluate sound localization ability. This article discusses the implications of this research for clinical practice and evaluation of localization skills, especially for children.

Keywords: acoustic change complex; auditory evoked potential; minimum audible angle; sound localization; sound localization discrimination.