Auinger Alice Barbara, Liepins Rudolfs, Kaider Alexandra, Vyskocil Erich, Riss Dominik, Arnoldner Christoph
Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria.
Center for Medical Statistics, Informatics, and Intelligent Systems, Medical University of Vienna, Vienna, Austria.
Ear Hear. 2021 May/Jun;42(3):709-717. doi: 10.1097/AUD.0000000000000973.
Temporal fine structure information such as low-frequency sounds including the fundamental frequency (F0) is important to separate different talkers in noisy environments. Speech perception in noise is negatively affected by reduced temporal fine structure resolution in cochlear hearing loss. It has been shown that normal-hearing (NH) people as well as cochlear implant patients with preserved acoustic low-frequency hearing benefit from different F0 between concurrent talkers. Though patients with an active middle ear implant (AMEI) report better sound quality compared with hearing aids, they often struggle when listening in noise. The primary objective was to evaluate whether or not patients with a Vibrant Soundbridge AMEI were able to benefit from F0 differences in a concurrent talker situation and if the effect was comparable to NH individuals.
A total of 13 AMEI listeners and 13 NH individuals were included. A modified variant of the Oldenburg sentence test was used to emulate a concurrent talker scenario. One sentence from the test corpus served as the masker and the remaining sentences as target speech. The F0 of the masker sentence was shifted upward by 4, 8, and 12 semitones. The target and masker sentences were presented simultaneously to the study subjects and the speech reception threshold was assessed by adaptively varying the masker level. To evaluate any impact of the occlusion effect on speech perception, AMEI listeners were tested in two configurations: with a plugged ear-canal contralateral to the implant side, indicated as AMEIcontra, or with both ears plugged, indicated as AMEIboth.
In both study groups, speech perception improved when the F0 difference between target and masker increased. This was significant when the difference was at least 8 semitones; the F0-based release from masking was 3.0 dB in AMEIcontra (p = 0.009) and 2.9 dB in AMEIboth (p = 0.015), compared with 5.6 dB in NH listeners (p < 0.001). A difference of 12 semitones revealed a F0-based release from masking of 3.5 dB in the AMEIcontra (p = 0.002) and 3.4 dB in the AMEIboth (p = 0.003) condition, compared with 5.0 dB in NH individuals (p < 0.001).
Though AMEI users deal with problems resulting from cochlear damage, hearing amplification with the implant enables a masking release based on F0 differences when F0 between a target and masker sentence was at least 8 semitones. Additional occlusion of the ear canal on the implant side did not affect speech performance. The current results complement the knowledge about the benefit of F0 within the acoustic low-frequency hearing.
诸如包括基频（F0）在内的低频声音等时间精细结构信息，对于在嘈杂环境中区分不同说话者很重要。在耳蜗性听力损失中，时间精细结构分辨率降低会对噪声中的言语感知产生负面影响。研究表明，听力正常（NH）的人以及保留了低频听力的人工耳蜗植入患者，会从同时说话者之间不同的F0中受益。尽管主动式中耳植入（AMEI）患者报告称与助听器相比声音质量更好，但他们在噪声环境中聆听时往往仍有困难。主要目的是评估使用Vibrant Soundbridge AMEI的患者在同时说话者情境中是否能够从F0差异中受益，以及这种效果是否与NH个体相当。
共纳入13名AMEI聆听者和13名NH个体。使用了Oldenburg句子测试的改良变体来模拟同时说话者场景。测试语料库中的一个句子用作掩蔽声，其余句子用作目标语音。掩蔽声声句的F0向上移动4、8和12个半音。目标句和掩蔽句同时呈现给研究对象，并通过自适应改变掩蔽声水平来评估言语接受阈值。为了评估堵塞效应对言语感知的任何影响，AMEI聆听者在两种配置下进行测试：植入侧对侧耳道堵塞，记为AMEIcontra，或双耳堵塞，记为AMEIboth。
在两个研究组中，当目标句和掩蔽句之间的F0差异增加时，言语感知均有所改善。当差异至少为8个半音时，这种改善具有显著性；与NH聆听者的5.6 dB（p < 0.001）相比，基于F0的掩蔽解除在AMEIcontra中为3.0 dB（p = 0.009），在AMEIboth中为2.9 dB（p = 0.015）。12个半音的差异显示，在AMEIcontra条件下基于F0的掩蔽解除为3.5 dB（p = 0.002），在AMEIboth条件下为3.4 dB（p = 0.003），而NH个体为5.0 dB（p < 0.001）。
尽管AMEI使用者面临耳蜗损伤导致的问题，但植入物的听力放大功能在目标句和掩蔽句之间的F0至少为8个半音时，能够实现基于F0差异的掩蔽解除。植入侧耳道的额外堵塞并未影响言语表现。当前结果补充了关于低频听力中F0益处的知识。
