View The Document

Accession Number:



Measurements of Cochlear Synaptopathy Using Electrocochleography


Author Organization(s):

Report Date:



Cochlear synaptopathy is a condition where hair cell function remains viable even though synaptic connection with the auditory nerve has been severed. As a means to test for the presence of this condition, it has long been recognized that electrocochleography (ECochG) provides an unparalleled and highly informative window into cochlear function. Experiments in animals using ototoxins and neurotoxins have allowed us to identify unique signatures of responses from hair cells and the auditory nerve, respectively. These have allowed us to identify unique metrics that are associated with synaptopathy. The goal of this project is to develop an innovative approach to use ECochG to serve as the centerpiece of a battery of differential tests focused on cochlear synaptopathy and its perceptual sequelae. This objective aligns itself precisely with the FY18 HRRP FARA Focus Area that calls for the development of methods to assess auditory dysfunction related to synaptopathy and hidden hearing loss. The plan is to develop ECochG measures that provide a detailed picture of the functional properties of an individuals hair cells and neural elements, and to relate this cochlear profile to auditory performance. The study includes both animal and human studies. Animal results with neurotoxins and human studies in subjects with various degrees of hearing loss are showing effects of synaptopathy on ECochG potentials recording from the round window that can be detected with our specialized analyses. The methods are being extended to ear canal recording with should have a broader clinical applicability. New results are also showing an unexpected sensitivity of responses to distortion products of multione stimuli to be sensitive to cochlear synaptopathy produced by neurotoxins.



File Size:





Communities of Interest:

Distribution Statement:

Approved For Public Release

View The Document