Modulation perception in listening difficulties (Petley et al., 2024)

<b>Purpose:</b> Amplitude modulations (AMs) are important for speech intelligibility, and deficits in speech intelligibility are a leading source of impairment in childhood listening difficulties (LiD). The present study aimed to explore the relationships between AM perception and speech-in-noise (SiN) comprehension in children and to determine whether deficits in AM processing contribute to childhood LiD. Evoked responses were used to parse the neural origins of AM processing.<b>Method:</b> Forty-one children with LiD and 44 typically developing children, ages 8–16 years, participated in the study. Behavioral AM depth thresholds were measured at 4 and 40 Hz. SiN tasks included the Listening in Spatialized Noise–Sentences Test (LiSN-S) and a coordinate response measure (CRM)–based task. Evoked responses were obtained during an AM change detection task using alternations between 4 and 40 Hz, including the N1 of the acoustic change complex, auditory steady-state response (ASSR), P300, and a late positive response (late potential [LP]). Maturational effects were explored via age correlations.<b>Results:</b> Age correlated with 4-Hz AM thresholds, CRM separated talker scores, and N1 amplitude. Age-normed LiSN-S scores obtained without spatial or talker cues correlated with age-corrected 4-Hz AM thresholds and area under the LP curve. CRM separated talker scores correlated with AM thresholds and area under the LP curve. Most behavioral measures of AM perception correlated with the signal-to-noise ratio and phase coherence of the 40-Hz ASSR. AM change response time also correlated with area under the LP curve. Children with LiD exhibited deficits with respect to 4-Hz thresholds, AM change accuracy, and area under the LP curve.<b>Conclusions:</b> The observed relationships between AM perception and SiN performance extend the evidence that modulation perception is important for understanding SiN in childhood. In line with this finding, children with LiD demonstrated poorer performance on some measures of AM perception, but their evoked responses implicated a primarily cognitive deficit.<b>Supplemental Material S1.</b> EEG denoising and ERP data quality metrics. Number of ICA components rejected and number of trials accepted for averaging are reported as mean (SD). Measurement windows for ERP amplitudes and areas under the curve are reported as window limits, in milliseconds.Petley, L., Blankenship, C., Hunter, L. L., Stewart, H. J., Lin, L., &amp; Moore, D. R. (2024). Amplitude modulation perception and cortical evoked potentials in children with listening difficulties and their typically developing peers. <i>Journal of Speech, Language, and Hearing Research, 67</i>(2), 633–656. https://doi.org/10.1044/2023_JSLHR-23-00317

**研究目的**：振幅调制（Amplitude modulations, AMs）对言语清晰度至关重要，而言语清晰度缺陷是儿童听觉障碍（childhood listening difficulties, LiD）的核心致病因素之一。本研究旨在探讨儿童振幅调制感知与噪声下言语理解（speech-in-noise, SiN）之间的关联，并明确振幅调制加工缺陷是否会导致儿童听觉障碍。本研究采用诱发电位（evoked responses）解析振幅调制加工的神经起源。
**研究方法**：本研究共招募41名儿童听觉障碍患儿与44名年龄匹配的典型发育儿童，年龄范围为8~16岁。研究分别在4 Hz与40 Hz条件下测量了行为学振幅调制深度阈值。噪声下言语理解任务包括空间化噪声下言语句子测试（Listening in Spatialized Noise–Sentences Test, LiSN-S）以及基于坐标反应测量（coordinate response measure, CRM）的任务。在4 Hz与40 Hz交替的振幅调制变化检测任务中采集诱发电位，涵盖声学变化复合波（acoustic change complex）的N1成分、听觉稳态反应（auditory steady-state response, ASSR）、P300以及晚正反应（late potential [LP]）。通过年龄相关性分析探讨发育成熟的影响效应。
**研究结果**：年龄与4 Hz振幅调制阈值、坐标反应测量分离说话人得分以及N1振幅呈显著相关。无空间线索与说话人线索的年龄标准化空间化噪声下言语句子测试得分，与年龄校正后的4 Hz振幅调制阈值以及晚正反应曲线下面积呈显著相关。坐标反应测量分离说话人得分与振幅调制阈值以及晚正反应曲线下面积显著相关。多数振幅调制感知的行为学指标与40 Hz听觉稳态反应的信噪比与相位一致性相关。振幅调制变化反应时同样与晚正反应曲线下面积相关。儿童听觉障碍患儿在4 Hz振幅调制阈值、振幅调制变化准确率以及晚正反应曲线下面积方面均表现出缺陷。
**研究结论**：本研究观察到的振幅调制感知与噪声下言语理解表现之间的关联，进一步证实了调制感知对儿童噪声下言语理解的重要性。与该发现一致，儿童听觉障碍患儿在部分振幅调制感知任务中表现更差，但其诱发电位结果提示其核心缺陷为认知层面的功能异常。
**补充材料S1**：脑电图（electroencephalogram, EEG）去噪与事件相关电位（event-related potential, ERP）数据质量指标。被剔除的独立成分分析（Independent Component Analysis, ICA）成分数量以及用于平均的有效试次数量以均值（标准差，standard deviation, SD）形式报告。事件相关电位振幅与曲线下面积的测量窗口以毫秒为单位的窗口范围形式给出。
Petley, L.、Blankenship, C.、Hunter, L. L.、Stewart, H. J.、Lin, L. 与 Moore, D. R.（2024）。《儿童听觉障碍患儿与典型发育同伴的振幅调制感知与皮层诱发电位》。*Journal of Speech, Language, and Hearing Research*，67(2)，633–656。https://doi.org/10.1044/2023_JSLHR-23-00317