Riazi Mariam, Ferraro John A
Hearing and Speech Department, University of Kansas Medical Center, 3031 Miller, 3901 Rainbow Boulevard, Kansas City, KS 66160-7605, USA.
J Am Acad Audiol. 2008 Jan;19(1):46-55. doi: 10.3766/jaaa.19.1.5.
The cochlear microphonic (CM) may play an important role in the diagnosis of auditory neuropathy (AN) in newborns. However, since the CM tends to mirror the waveform of the acoustic stimulus, conscientious recording methodology must be applied to separate true response from artifact. The difficulty in achieving this separation has limited the clinical usefulness of the CM. In an effort to call attention to the importance of recording protocol when measuring the CM, the present study was designed to optimize CM recordings in humans by investigating the following parameters: (1) secondary minus electrode recording site (mastoid versus ear canal [EC]), (2) stimulus parameters, and (3) grounding and shielding conditions. Normative data were collected in full-term newborns (n = 7) and adults (n = 4) with no known risk factors for cochlear or retrocochlear pathology. Results suggest that the CM is easier to separate from stimulus artifact using an EC electrode and toneburst stimuli. In addition, electromagnetic shielding and grounding of the electrode cables and the acoustic transducer were effective in reducing and/or eliminating stimulus artifact. Results from this normative study may be helpful in improving the diagnostic utility of the CM in AN and other hearing-related disorders.
耳蜗微音电位（CM）可能在新生儿听神经病（AN）的诊断中发挥重要作用。然而，由于CM往往反映声刺激的波形，因此必须采用严谨的记录方法，以将真实反应与伪迹区分开来。实现这种区分的困难限制了CM的临床应用价值。为了引起人们对测量CM时记录方案重要性的关注，本研究旨在通过研究以下参数来优化人体CM记录：（1）辅助减电极记录部位（乳突与耳道[EC]），（2）刺激参数，以及（3）接地和屏蔽条件。收集了足月新生儿（n = 7）和成人（n = 4）的规范数据，这些人没有已知的耳蜗或蜗后病变风险因素。结果表明，使用EC电极和短纯音刺激更容易将CM与刺激伪迹区分开来。此外，电极电缆和声换能器的电磁屏蔽和接地有效地减少和/或消除了刺激伪迹。这项规范研究的结果可能有助于提高CM在AN和其他听力相关疾病中的诊断效用。
