Abstract The dorsal cochlear nucleus (DCN) integrates auditory and somatosensory information through circuitry that modulates activity of the principal output neurons of the circuit, the fusiform cells. Fusiform cells receive somatosensory information via synapses on their apical dendrites and acoustic information via their basal dendrites. When somatosensory activation is combined with sound, the circuit can be strengthened or weakened depending on the order of the bimodal stimuli. This process is called stimulus timing dependent plasticity. In the condition of phantom sound perception, or tinnitus, the DCN circuitry is strengthened to increase the firing rates and synchrony of fusiform cells. This proposal seeks to investigate the effects of manipulations on the circuitry of this first auditory brainstem nucleus by implementing a bimodal sound + electrical stimulus paradigm to alter the circuit in normal and pathological conditions. Animal and human studies will be conducted to optimize the stimulation parameters/dosages necessary to weaken the circuit and thus ameliorate the pathological condition. This will ultimately lead to treatments for neural disorders involving hyperactive or hyper synchronous circuits such as those identified for tinnitus or Parkinson's disease.