Oh Yonghee, Reiss Lina A J
Department of Otolaryngology, Oregon Health and Science University, Portland, Oregon 97239, USA.
J Acoust Soc Am. 2017 Aug;142(2):780. doi: 10.1121/1.4997190.
Both bimodal cochlear implant and bilateral hearing aid users can exhibit broad binaural pitch fusion, the fusion of dichotically presented tones over a broad range of pitch differences between ears [Reiss, Ito, Eggleston, and Wozny. (2014). J. Assoc. Res. Otolaryngol. 15(2), 235-248; Reiss, Eggleston, Walker, and Oh. (2016). J. Assoc. Res. Otolaryngol. 17(4), 341-356; Reiss, Shayman, Walker, Bennett, Fowler, Hartling, Glickman, Lasarev, and Oh. (2017). J. Acoust. Soc. Am. 143(3), 1909-1920]. Further, the fused binaural pitch is often a weighted average of the different pitches perceived in the two ears. The current study was designed to systematically measure these pitch averaging phenomena in bilateral hearing aid users with broad fusion. The fused binaural pitch of the reference-pair tone combination was initially measured by pitch-matching to monaural comparison tones presented to the pair tone ear. The averaged results for all subjects showed two distinct trends: (1) The fused binaural pitch was dominated by the lower-pitch component when the pair tone was either 0.14 octaves below or 0.78 octaves above the reference tone; (2) pitch averaging occurred when the pair tone was between the two boundaries above, with the most equal weighting at 0.38 octaves above the reference tone. Findings from two subjects suggest that randomization or alternation of the comparison ear can eliminate this asymmetry in the pitch averaging range. Overall, these pitch averaging phenomena suggest that spectral distortions and thus binaural interference may arise during binaural stimulation in hearing-impaired listeners with broad fusion.
双模人工耳蜗使用者和双侧助听器使用者都能表现出广泛的双耳音高融合，即双耳呈现的音调在两耳间广泛的音高差异范围内融合[赖斯、伊藤、埃格尔斯顿和沃兹尼。（2014年）。《耳鼻咽喉研究协会杂志》15(2)，235 - 248；赖斯、埃格尔斯顿、沃克和吴。（2016年）。《耳鼻咽喉研究协会杂志》17(4)，341 - 356；赖斯、谢伊曼、沃克、贝内特、福勒、哈特林、格利克曼、拉萨列夫和吴。（2017年）。《美国声学学会杂志》143(3)，1909 - 1920]。此外，融合的双耳音高通常是两耳中感知到的不同音高的加权平均值。本研究旨在系统测量具有广泛融合能力的双侧助听器使用者的这些音高平均现象。参考对音调组合的融合双耳音高最初通过与呈现给对音调耳朵的单耳比较音调进行音高匹配来测量。所有受试者的平均结果显示出两种不同的趋势：（1）当对音调比参考音调低0.14倍频程或高0.78倍频程时，融合的双耳音高由低音调成分主导；（2）当对音调在上述两个边界之间时会出现音高平均，在比参考音调高0.38倍频程时加权最为均等。两名受试者的研究结果表明，比较耳朵的随机化或交替可以消除音高平均范围内的这种不对称性。总体而言，这些音高平均现象表明，在具有广泛融合能力的听力受损听众的双耳刺激过程中，可能会出现频谱失真，进而产生双耳干扰。
