Utilizing stochastic resonance phenomenons in the central auditory system for tinnitus therapy

• Applicants: Privatdozent Dr. Patrick Krauss; Dr. Konstantin Tziridis
• Subject Area: Otolaryngology, Phoniatrics and Audiology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 510395418

Subjective Tinnitus is a common symptom with a prevalence of 10 to 20% of the population and therefor counts as one of the major widespread diseases in western societies. In Germany alone, the yearly incidence rate sums up to 270.000 new chronic tinnitus cases. It is generally believed, that tinnitus development is caused by a hearing impairment, be it either clinically relevant hearing loss or so-called hidden hearing loss. In this context, especially relevant are the from tinnitus resulting central nervous co-morbidities like depression, anxiety or insomnia that can lead to social isolation and depression up to suicide. Hence that major burden of the affected patients no real therapy for chronic tinnitus exists until now. The main reason for that lack of therapy is the missing of the complete understanding of the neurophysiological mechanisms leading to the development of the phantom percept after the initial hearing loss. Common models of tinnitus development can only describe parts of the aspects of the phenomenon, yet. For that, our work group is engaged in basic research for several years to unravel these neurophysiological mechanisms. Recently, we developed a new model of tinnitus development that is based on data from animal experiments, human patient data and neuronal network models. This new model is able to make verifiable predictions that allowed us a completely new sight on the tinnitus phenomenon. From this view, tinnitus is a side product of a physiological mechanism utilizing stochastic resonance (SR) for constantly optimizing information transmission into the auditory system and therefor optimizing hearing. Taken together our model of tinnitus development predicts that the auditory system increases internal neuronal noise at the 2nd synapse by SR and therefor rescuing hearing thresholds after a hearing loss. That internal neuronal noise is then propagated along the auditory pathway up to the auditory cortex and there perceived as tinnitus. Based on this model we already developed a new therapeutic strategy – replacement of the internal neuronal noise by external auditory noise – and documented it in two recent pilot studies under my supervision and in cooperation with Dr. Krauss.In the present revised proposal, we want to test this new method in a translational approach for its practical applicability and investigate the specific parameter settings of the used hearing aids for stimulus generation in detail. For that means we are supported by the WSAudiology Sivantos GmbH that provides the hearing aids and additional technical support.

• DFG Programme: Research Grants