Wideband acoustic absorbance in children with Down syndrome,

Abstract Introduction: Tympanometry is currently the most frequently used tool for assessing the status of the middle ear, commonly assessed using a single 226 Hz tone. However, the use of the Acoustic Immittance Measures with a wideband stimulus is a promising high-resolution evaluation, especially in individuals known to have middle ear alterations, such as Down syndrome patients. Objective: The aim of this study was to analyze the acoustic absorbance measurements in children with Down syndrome. Methods: Cross-sectional study, approved by the institution's ethics committee. Data were collected from 30 children, with a mean age of 8.4 years, 15 with Down syndrome (DS-study group) and 15 children with typical development and no hearing complaints (control group). Energy absorbance was measured at frequencies of 226-8000 Hz at ambient pressure and at peak pressure as a function of frequency using TITAN equipment. Statistical analysis was performed using the established level of statistical significance of 5%. Results: With the 226 Hz probe tone, 30 ears of the control group and 22 of the study group exhibited Type A tympanograms, whereas Type B was observed in eight children in the study group. The mean acoustic absorbance ratio of the study group was lower than that of the control group at frequencies centered at 2520 Hz (p = 0.008) for those with normal tympanometry results, and 226-4000 Hz (p < 0.03) for those with a Type B tympanometry curve. Conclusion: The low energy absorption in the presence of normal tympanograms in children with Down syndrome may suggest middle ear abnormalities.

摘要引言：鼓室压测量（tympanometry）是目前临床评估中耳状态最常用的检测手段，常规多采用226 Hz单频探测音。然而，采用宽频刺激的声导抗测试（acoustic immittance measures）是一种极具前景的高分辨率评估方法，尤其适用于已确诊存在中耳病变的人群，如唐氏综合征（Down syndrome）患者。
研究目的：本研究旨在分析唐氏综合征患儿的声吸收测量结果。
研究方法：本研究为横断面研究，已通过机构伦理委员会审批。共纳入30名儿童，平均年龄8.4岁，其中15例为唐氏综合征患儿（研究组，DS），另15例为发育正常且无听力主诉的儿童（对照组）。采用TITAN设备，分别在环境压及峰压下，于226~8000 Hz频率范围内测量能量吸收值。统计学检验以5%作为统计学显著性阈值。
研究结果：以226 Hz探测音检测时，对照组30耳及研究组22耳均表现为A型鼓室图，研究组另有8名儿童表现为B型鼓室图。在鼓室图结果正常的受试者中，研究组在中心频率为2520 Hz处的平均声吸收比低于对照组（p=0.008）；在B型鼓室图受试者中，研究组在226~4000 Hz频率范围内的平均声吸收比低于对照组（p<0.03）。
研究结论：唐氏综合征患儿在鼓室图结果正常的情况下仍呈现低能量吸收，该结果提示其可能存在中耳异常。