FPGA System Design of a Cochlear Research Platform to Support Bimodal (EAS) and Variable Rate Electric Stimulation

The extensive research and continuous improvements in sound processing strategies play a significant role in the advancement of cochlear implants and hearing aid technologies. Cochlear implants are characterized by different parameters such as electrode number, current level, pulse type, width, etc., in addition to a wide variety of signal processing strategies. This variety of choices and parameters provide researchers numerous challenges to implement novel strategies or perform perceptual studies. Therefore, the need for effective research tools and interfaces in the research community is growing rapidly. The existing interfaces either have limited functionalities or are not suitable for conducting a broad range of experiments. Portability, wearability, and ease of programmability limits existing research interfaces to benchtop/laboratory use only. Real world, long-term subject evaluations are needed to assess the true potential of novel sound processing strategies. There exists the compelling scientific evidence to support benefits obtained by bimodal hearing (i.e., CI in one ear and HA in the contralateral ear) for improved speech recognition in quiet and in noise, as well as for lateralization and localization issues. Studies support the speech performance improvement for high rate pulse stimulations. The work in this thesis extends the existing CCi-MOBILE platform’s bilateral electric only capability to support both electric plus acoustic stimulation as well as variable rate electric stimulation. This research platform aims to perform acute laboratory based and chronic field studies without compromising portability and wearability.