Keefe Douglas H, Porter Heather L, Fitzpatrick Denis F
Boys Town National Research Hospital, 555 North 30th Street, Omaha, Nebraska 68131, USA.
J Acoust Soc Am. 2025 May 1;157(5):3638-3654. doi: 10.1121/10.0036648.
The curved centerline of the ear canal, and its spatial variations of area, transverse to this centerline influence sound transmission in the human ear canal at higher frequencies. The area function was directly assessed from images obtained using a hand-held device inserted into the canal and compared to sound area functions indirectly calculated from acoustical measurements. For shape data, areas were calculated by modeling each canal cross section as an ellipse. In a discrete Frenet frame procedure, the shape outputs were the spatial variations of ellipse area and eccentricity, with the curvature and torsion parameters representing the centerline. The resulting shape area functions were compared with sound area functions by finding the best alignment of the functions in each ear. The median shape and sound areas of the ear canal agreed within 0.3 mm2 at the probe tip and approximately 6 mm2 at 3.6 and 7.2 mm lateral to the probe tip. This supports the potential use of acoustical assessment of ear-canal area in future research.
耳道的弯曲中心线及其垂直于该中心线的面积空间变化会影响高频下人耳道内的声音传播。通过使用插入耳道的手持设备获取的图像直接评估面积函数，并将其与通过声学测量间接计算出的声音面积函数进行比较。对于形状数据，通过将每个耳道横截面建模为椭圆来计算面积。在离散的弗伦内特标架过程中，形状输出是椭圆面积和偏心率的空间变化，曲率和挠率参数表示中心线。通过找到每只耳朵中函数的最佳对齐方式，将得到的形状面积函数与声音面积函数进行比较。耳道的形状和声音面积中位数在探头尖端处相差0.3平方毫米以内，在探头尖端外侧3.6毫米和7.2毫米处相差约6平方毫米。这支持了在未来研究中对耳道面积进行声学评估的潜在用途。
