Bimodal Auditory Electrical Stimulation for the Treatment of Tinnitus: Preclinical and Clinical Studies

An Exploratory Study of Bimodal Electro-Aural Stimulation Through the Ear Canals for Tinnitus

OBJECTIVE

The aim of this study was to explore the potential for bimodal auditory and noninvasive electrical stimulation at the ears to alleviate tonal, somatic tinnitus that was investigated in a small preliminary trial (11 participants).

DESIGN

Auditory stimulation took the form of short "notched noise" bursts customized to each participant's tinnitus percept. Simultaneous pulsed electrical stimulation, intended to facilitate neuroplasticity, was delivered via hydrogel electrodes placed in opposite ears.

RESULTS

After a 6-week intervention period, average Tinnitus Functional Index (TFI) and Tinnitus Primary Function Questionnaire (TPFQ) scores were consistent with clinically meaningful improvements in the study population. Magnitudes and effect sizes of improvements in TFI and TPFQ are comparable to those reported in other recent bimodal therapy studies using different auditory and electrical stimulation parameters.

CONCLUSIONS

Our results should be considered preliminary given the small sample size, lack of crossover data, and small subject pool. When considered alongside other recent bimodal therapy results, we do believe that there are therapeutic benefits of bimodal stimulation for tinnitus sufferers that have the potential to help some with tinnitus, with a variety of stimulation parameters and electrode placements.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25444546.

Too Blind to See the Elephant? Why Neuroscientists Ought to Be Interested in Tinnitus

A curative therapy for tinnitus currently does not exist. One may actually exist but cannot currently be causally linked to tinnitus due to the lack of consistency of concepts about the neural correlate of tinnitus. Depending on predictions, these concepts would require either a suppression or enhancement of brain activity or an increase in inhibition or disinhibition. Although procedures with a potential to silence tinnitus may exist, the lack of rationale for their curative success hampers an optimization of therapeutic protocols. We discuss here six candidate contributors to tinnitus that have been suggested by a variety of scientific experts in the field and that were addressed in a virtual panel discussion at the ARO round table in February 2021. In this discussion, several potential tinnitus contributors were considered: (i) inhibitory circuits, (ii) attention, (iii) stress, (iv) unidentified sub-entities, (v) maladaptive information transmission, and (vi) minor cochlear deafferentation. Finally, (vii) some potential therapeutic approaches were discussed. The results of this discussion is reflected here in view of potential blind spots that may still remain and that have been ignored in most tinnitus literature. We strongly suggest to consider the high impact of connecting the controversial findings to unravel the whole complexity of the tinnitus phenomenon; an essential prerequisite for establishing suitable therapeutic approaches.

A State-of-Art Review of Digital Technologies for the Next Generation of Tinnitus Therapeutics

Background: Digital processing has enabled the development of several generations of technology for tinnitus therapy. The first digital generation was comprised of digital Hearing Aids (HAs) and personal digital music players implementing already established sound-based therapies, as well as text based information on the internet. In the second generation Smart-phone applications (apps) alone or in conjunction with HAs resulted in more therapy options for users to select from. The 3rd generation of digital tinnitus technologies began with the emergence of many novel, largely neurophysiologically-inspired, treatment theories that drove development of processing; enabled through HAs, apps, the internet and stand-alone devices. We are now of the cusp of a 4th generation that will incorporate physiological sensors, multiple transducers and AI to personalize therapies. Aim: To review technologies that will enable the next generations of digital therapies for tinnitus. Methods: A "state-of-the-art" review was undertaken to answer the question: what digital technology could be applied to tinnitus therapy in the next 10 years? Google Scholar and PubMed were searched for the 10-year period 2011-2021. The search strategy used the following key words: "tinnitus" and ["HA," "personalized therapy," "AI" (and "methods" or "applications"), "Virtual reality," "Games," "Sensors" and "Transducers"], and "Hearables." Snowballing was used to expand the search from the identified papers. The results of the review were cataloged and organized into themes. Results: This paper identified digital technologies and research on the development of smart therapies for tinnitus. AI methods that could have tinnitus applications are identified and discussed. The potential of personalized treatments and the benefits of being able to gather data in ecologically valid settings are outlined. Conclusions: There is a huge scope for the application of digital technology to tinnitus therapy, but the uncertain mechanisms underpinning tinnitus present a challenge and many posited therapeutic approaches may not be successful. Personalized AI modeling based on biometric measures obtained through various sensor types, and assessments of individual psychology and lifestyles should result in the development of smart therapy platforms for tinnitus.