Dysphagia, or difficulty swallowing, is a common symptom of many neurological diseases but its treatment is not well established or easily accessible. To start addressing this gap, the researchers developed and validated a cost-effective wearable surface electromyography (sEMG) biofeedback sensor technology (i-Phagia), optimized to record muscle activity from the head/neck and provide biofeedback to patients and adherence data to clinicians during swallow therapy. This system has been developed with commercially available and widely used materials and the Purdue University IRB has determined that the device is non-significant risk device. The goal of this clinical trial is to learn if this biofeedback (using this new technology/i-Phagia) when used as an adjunct to a standard swallow therapy protocol works to improve swallowing function in patients post chronic stroke or diagnosed with Parkinson's disease. It will also help the investigators learn whether this therapy protocol is equally effective when provided in-person versus via telehealth. Finally, it will determine which patient factors may influence how well the treatment works. The main questions it aims to answer are: * Does biofeedback (using this new technology/i-Phagia) when used as an adjunct to a standard swallow therapy protocol works better than a standard of care treatment to improve swallowing function in patients post chronic stroke or diagnosed with Parkinson's disease? * Is completing the swallow therapy protocol at home (via telehealth) as effective as completing it in-person (in the clinic)? * What factors related to the patients (e.g., age, diagnosis, etc.) may influence how well the treatment works? Participants will: * Complete a 12-week swallow treatment protocol (12 treatment visits) either in-person or at home (via telehealth) * Complete 3 in-person evaluations (pre-treatment; post-treatment; and at a 12-week post treatment follow-up time point) * Exercise at home several days per week and keep a diary/log of their home exercise The hypothesis is that upon study completion, the efficacy of sEMG biofeedback-facilitated swallow therapy for both in-person and telehealth service delivery in two neurogenic dysphagia populations will have been established, and variables determining response to treatment will begin to be identified.