Auditory Research Center, Caruso Department of Otolaryngology, University of Southern California, Los Angeles, CA, 90033, USA.
Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, 90089, USA.
J Assoc Res Otolaryngol. 2022 Oct;23(5):647-664. doi: 10.1007/s10162-022-00857-z. Epub 2022 Jul 8.
Otoacoustic emissions (OAEs) arise from one (or a combination) of two basic generation mechanisms in the cochlea: nonlinear distortion and linear reflection. As a result of having distinct generation processes, these two classes of emissions may provide non-redundant information about hair-cell integrity and show distinct sensitivities to cochlear pathology. Here, we characterize the relationship between reflection and distortion emissions in normal hearers across a broad frequency and stimulus-level space using novel analysis techniques. Furthermore, we illustrate the promise of this approach in a small group of individuals with mild-moderate hearing loss. A "joint-OAE profile" was created by measuring interleaved swept-tone stimulus-frequency OAEs (SFOAEs) and 2f-f distortion-product OAEs (DPOAEs) in the same ears using well-considered parameters. OAE spectra and input/output functions were calculated across five octaves. Using our specific recording protocol and analysis scheme, SFOAEs in normal hearers had higher levels than did DPOAEs, with the most pronounced differences occurring at the highest stimulus levels. Also, SFOAE compression occurred at higher stimulus levels (than did DPOAE compression) and its growth in the compressed region was steeper. The diagnostic implications of these findings and the influence of the measurement protocol on both OAEs (and on their relationship) are discussed.
耳声发射（OAE）源于耳蜗中两种基本产生机制之一（或组合）：非线性失真和线性反射。由于具有不同的产生过程，这两类发射可能提供有关毛细胞完整性的非冗余信息，并对耳蜗病理表现出不同的敏感性。在这里，我们使用新颖的分析技术，在广泛的频率和刺激水平空间中描述正常听力者中反射和失真发射之间的关系。此外，我们在一小群轻度至中度听力损失的个体中说明了这种方法的前景。通过使用经过深思熟虑的参数，在同一耳朵中测量交错扫频刺激频率耳声发射（SFOAE）和 2f-f 失真产物耳声发射（DPOAE），创建了“联合 OAE 谱”。在五个倍频程上计算 OAE 谱和输入/输出函数。在正常听力者中，与 DPOAE 相比，SFOAE 的水平更高，在最高刺激水平下差异最明显。此外，SFOAE 压缩发生在更高的刺激水平（比 DPOAE 压缩），并且在压缩区域中的增长更陡峭。讨论了这些发现的诊断意义以及测量方案对两种 OAE（及其关系）的影响。
