Loss of communication is one of the most devastating consequences of severe paralysis from a range of disorders, including ALS, stroke, and muscular dystrophy. Recent and ongoing studies have demonstrated the ability to decode words and sentences directly from the neural activity of a paralyzed individual who cannot speak. This success highlights the feasibility of synthesized speech decoded from neural signals using electrocorticography and lays critical groundwork for the development of a fully implantable speech prosthesis. A total implantable device will eliminate physical tethering, reduce infection risk, enable mobile, on-the-go use, expand communication training and capability, and improve patient autonomy and quality of life. Accordingly, we propose to finalize the development of a fully implantable speech prosthesis device system designed to restore real-time communication for patients suffering from severe dysarthria or anarthria. The system features a wireless brain interface device for ECoG recording, digitalization and data streaming and an external portable computer receiving data and hosting real-time speech decoding algorithms. Here, we will complete development and testing of the 3D electronic packaging, the electrode array, and peripherals to enable full integration of the device; undertake device manufacturing and perform functional and safety testing; obtain an FDA IDE; and perform intra-operative clinical studies to optimize the electrode interface and verify critical aspects of device performance. These studies will provide critical groundwork for future chronic implantation trials and subsequent commercialization.