Speech envelope following responses in children (Easwar et al., 2022)

Purpose: Envelope following responses (EFRs) could be useful for objectively evaluating audibility of speech in children who are unable to participate in routine clinical tests. However, relative to adults, the characteristics of EFRs elicited by frequency-specific speech and their utility in predicting audibility in children are unknown.
Method: EFRs were elicited by the first (F1) and second and higher formants (F2+) of male-spoken vowels /u/ and /i/ and by fricatives /ʃ/ and /s/ in the token /suʃi/ presented at 15, 35, 55, 65, and 75 dB SPL. The F1, F2+, and fricatives were low-, mid-, and high-frequency dominant, respectively. EFRs were recorded between the vertex and the nape from twenty-three 6- to 17-year-old children and 21 young adults with normal hearing. Sensation levels of stimuli were estimated based on behavioral thresholds.
Results: In children, amplitude decreased with age for /ʃ/-elicited EFRs but remained stable for low- and mid-frequency stimuli. As a group, EFR amplitude and phase coherence did not differ from that of adults. EFR sensitivity (proportion of audible stimuli detected) and specificity (proportion of inaudible stimuli not detected) did not vary between children and adults. Consistent with previous work, EFR sensitivity increased with stimulus frequency and level. The type of statistical indicator used for EFR detection did not influence accuracy in children.
Conclusions: Adultlike EFRs in 6- to 17-year-old typically developing children suggest mature envelope encoding for low- and mid-frequency stimuli. EFR sensitivity and specificity in children, when considering a wide range of stimulus levels and audibility, are ~77% and ~92%, respectively.

Supplemental Material S1. EFR sensitivity (Table 1A) and specificity (Table 1B) at each level for each stimulus and statistical indicator in children and adults.

Easwar, V., Purcell, D., Lasarev, M., McGrath, E., & Galloy, M. (2022). Speech-evoked envelope following responses in children and adults. Journal of Speech, Language, and Hearing Research. Advance online publication. https://doi.org/10.1044/2022_JSLHR-22-00156

目的：封套跟随反应（EFRs）可用于客观评估无法参与常规临床测试的儿童语音可听性。然而，与成人相比，由特定频率的语音激发的EFRs的特征及其在预测儿童语音可听性方面的效用尚不清楚。
方法：通过男性发音元音/u/和/i/的第一（F1）和第二及更高形式音（F2+），以及/suʃi/音素中的擦音/ʃ/和/s/激发EFRs，激发频率分别为15、35、55、65和75 dB SPL。F1、F2+和擦音分别对应低频、中频和高频主导。EFRs记录自23名6至17岁的儿童和21名听力正常的年轻成人，记录点位于头顶和颈部之间。基于行为阈值估计刺激的感知水平。
结果：在儿童中，由/ʃ/激发的EFRs的振幅随年龄增长而减小，而低频和中频刺激的振幅保持稳定。就群体而言，EFR振幅和相位相干性与成人无显著差异。EFR敏感性（可听刺激检测比例）和特异性（未检测到的不可听刺激比例）在儿童和成人之间没有差异。与先前的研究一致，EFR敏感性随着刺激频率和水平的增加而增加。用于EFR检测的统计指标类型不影响儿童中的准确性。
结论：6至17岁典型发展儿童中成人般的EFRs表明低频和中频刺激的包络编码已成熟。在考虑广泛的刺激水平和可听性时，儿童的EFR敏感性和特异性分别为约77%和约92%。
补充材料S1：儿童和成人中，每个刺激和统计指标在各个水平上的EFR敏感度（表1A）和特异性（表1B）。
Easwar, V., Purcell, D., Lasarev, M., McGrath, E., & Galloy, M. (2022). 儿童和成人语音激发的封套跟随反应。言语、语言和听力研究杂志。在线预发表。https://doi.org/10.1044/2022_JSLHR-22-00156