At-home taVNS for Neurorehabilitation in Parkinson's Disease

Inclusion Criteria: * Issues with walking, balance, and gait as determined by a movement disorders neurologist (a score of equal to or greater than 1 on MDS-UPDRS items 2.12 (walking and balance), and 3.10 (gait)) * Diagnosis of idiopathic Parkinson's Disease based on UK Brain Bank diagnostic criteria * Hoehn and Yahr Stage 2-4 as determined by a movement disorders neurologist * Stable on dopaminergic medications over the past 30 days prior to enrollment in the study Exclusion Criteria: * A history of taVNS in the last 6 months * A history of brain surgery, traumatic brain injury or stroke * Diagnosis of a nervous system disorder besides PD, alcohol or substance use disorder, or unstable cardiovascular conditions * History of myocardial infarction or arrhythmia, bradycardia * A history of other significant gait impairment unrelated to PD (e.g. orthopedic deformities) * Inability to complete gait/ motor assessments (without assistance or assistance devices) * Ear trauma, facial pain, anatomical abnormalities or other barriers preventing earpiece fit * Failure to meet all criteria on a standardized MRI/taVNS safety screening: This includes, but is not limited to, the presence of claustrophobia, implanted electronic devices that are not 3T MRI compatible (e.g., pacemakers), metallic objects or fragments (e.g., bullets), and non-removable hair clips or piercings. * Individuals with a diagnosis of cognitive impairment (MoCA \< 24) that would make them unable to understand and follow study instructions or to consent for themselves. * Pregnancy * Visual hallucinations or other psychotic symptoms, other than mild visual hallucinations secondary to PD medications, not requiring treatment, or well controlled on stable doses of quetiapine or pimavenserin. * Individuals with a history of seizure(s) * Inability to perform at-home taVNS procedures safely and properly (either alone or with the aid of a caregiver) * Uncorrected visual or hearing impairments that would impact performance on cognitive tests or ability to follow study procedures * Use of B-Blockers, dopamine blocking agent (other than quetiapine or pimavenserin in stable doses), antiarrhythmic medication, acetylcholine esterase inhibitor (study doctor will consider if on stable doses), midodrine, fludrocortisone, droxidopa, or anticholinergic drugs