Diagnostics of the hearing organ by pulsed-DPOAE measurements of the ipsilateral olivocochlear reflex

• Applicants: Dr.-Ing. Ernst Dalhoff; Professor Dr. Anthony William Gummer
• Subject Area: Otolaryngology, Phoniatrics and Audiology ; Automation, Mechatronics, Control Systems, Intelligent Technical Systems, Robotics ; Medical Physics, Biomedical Technology
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 282627684

The aim of this project is to develop a new, highly accurate and objective method for diagnosting the hearing function in the clinical practice. To this end, so-called distorsion-product otoacoustic emissions are to be used. Otoacoustic emissions are a by-product of the cochlear amplifier, and are currently used to diagnose the state of the cochlear amplifier which relies on the outer hair cells. Less frequently, inner-hair cell function and the neural paths to the cortex via the brainstem can also be impaired. It is known that signals arriving at the brainstem are partly coupled back via efferent fibers projecting to the outer hair cells in the inner ear, where they change the operating point of the cochlear amplifier slightly. This effect is to be used for diagnosing hearing function including neural function up to the brainstem. Up to now, comparable approaches failed due to the fact that (i) changes of DPOAE due to efferent signaling are of tiny size and therefore hard to measure, and that (ii) DPOAE are prone to interference of two sources of their generation. Using a new, pulsed method to elicit DPOAE, we aim to achieve a more reliable diagnosis of this effect.

• DFG Programme: Research Grants