Asynchronous Stimulation for Cochlear Implants

1st Place, Engineering Division - 2012 Denman Undergraduate Research ForumThis thesis contributes the first psychoacoustic tests of Asynchronous Interleaved Sampling (AIS) performed with commercially available implants. AIS was originally proposed as an alternative to Continuous Interleaved Sampling (CIS) to demonstrate the benefit of asynchronous stimulation on conveying phase information. AIS automatically adjusts each channel's stimulation rate based on its relative temporal importance, mimicking the behavior of neurons. However, the algorithm was never tested with actual CI patients, so its claim of improving phase perception has stood unsubstantiated. The software design and implementation of AIS lays the groundwork for the first qualitative tests of the method's effect on phase discrimination. CI users participated in Schroeder phase discrimination (SPD) experiments to evaluate AIS's presentation of phase and temporal information. AIS performs comparably to CIS in SPD and in some cases introduces a new intelligible temporal cue. The results suggest that consideration of other factors such as electrode spacing and parameter adjustment may have the potential to improve the performance of asynchronous stimulation algorithms in CI devices. Asynchronous stimulation may also be applied to other technology, and represents a subject with rich synergy between engineering and biology.College of Engineering Undergraduate Research ScholarshipNo embarg