Acoustic Stimulation Paired With Body and Cortical Stimulation for Modulating Tinnitus

The purpose of the study is to investigate different stimulation parameters for a new noninvasive approach for modulating the brain that could potentially be beneficial for decreasing tinnitus perception. The new approach is called Multimodal Synchronization Therapy (mSync). mSync uses a combination of acoustic stimulation played through headphones and low levels of electrical current delivered via electrodes placed on the surface of different body regions. The timing interval between the acoustic and body stimulation is varied in order to cause different types of changes in the brain. In addition to acoustic and body stimulation, noninvasive cortical stimulation will also be presented as part of mSync to attempt to further modulate or decrease the tinnitus percept. Cortical stimulation will be performed by placing a magnetic coil over a spot on the head and sending a brief magnetic pulse that can travel through the skin and bone to create electrical current inside the head. For this study, different body locations as well as specific timing intervals among acoustic, body, and cortical stimulation will be investigated to identify appropriate parameters that can modulate and potentially decrease tinnitus perception. Different mSync parameters will be investigated across multiple testing sessions (up to 16 weekly sessions) and the tinnitus percept will be closely monitored throughout the study.

This study is not specifically seeking to treat tinnitus but is designed to investigate various mSync parameters that can alter the tinnitus percept. Findings from this study will help identify specific mSync parameters that can be more effective at decreasing or fully suppressing the tinnitus percept that will be systematically explored in a follow-up study.

Acoustic corresponds to noise sound stimulation. Body corresponds to body electrical stimulation. Cortical corresponds to transcranial magnetic stimulation. Acoustic is presented together with body and cortical stimulation. Different body locations and timing among acoustic, body, and cortical stimulation are presented across testing sessions.

Band-limited white noise stimulus, comfortable loudness level, presented via headphones or earphones with Tucker-Davis Technologies device.

Single pulse electrical stimulation on different body regions, comfortable current level, presented via surface pads or clips with Digitimer device.

Single pulse magnetic stimulation over frontal cortex, comfortable level at 110% resting motor threshold, presented via magnetic coil with Magstim device.

A series of questions to assess the quality and bothering nature of the tinnitus, which is then quantified into a single score.

A narrowband noise (from 2-12 kHz) is presented to the tinnitus ear and the minimum sound level (in decibel sound pressure level, decibel SPL) is determined that completely masks the tinnitus percept.

A series of questions to assess the quality and bothering nature of the tinnitus, which is then quantified into a single score.

Change in baseline description at an expected average of 5 minutes and 1.5 hours after testing paradigm

The subject adjusts the loudness and pitch (i.e., frequency) of a sound played to an ear to that of the tinnitus percept.

The subject describes the quality, characteristics and bothering nature of the tinnitus on a daily basis. The subject can also include any unusual or interesting events relating to the tinnitus that he/she feels would be relevant for the study.

Inclusion Criteria: Have subjective, non-pulsatile, and bothersome tinnitus Will not start any new tinnitus treatment during the study Ability to give informed consent and understand study objectives in English Willing and able to understand and comply with all study-related procedures Exclusion Criteria: Substantial hearing loss or hyperacusis that may interfere with the study Medical history of other ear or brain disorders, history of seizures, or currently using any medication or treatments that can cause or increase the chances of seizures Any implanted medical or metal device, such as a pacemaker, aneurysm clip, or cochlear implant Pregnant or currently breast-feeding (we need to give all female subjects a pregnancy test because pregnant females and unborn children need extra protection for their safety) Any handicap that prevents the subject from reliably performing the tests