New paper on combining current steering and current focusing is out!

EARLab is proud to announce the publication of a new paper: (Download here)

Padilla, M., Stupak, N., and Landsberger, D. M. (in press). "Pitch Ranking with Different Virtual Channel Configurations in Electrical Hearing," Hearing Research. pdf.

We introduce a new stimulation mode, the virtual tripole (VTP). The VTP is a tripole created from virtual channels to simultaneously provide current steering and current focusing. Hopefully using VTPs in a sound coding strategy provides the benefit of virtual channels (e.g. Fidelity 120) with the benefit of tripolar stimulation (e.g. Srinivasan et al., 2013).  

In this paper, we document that previous attempts at current focused virtual channels (e.g. the Quadrupolar Virtual Channel; Landsberger and Srinivasan, 2009) can provide an asymmetric distribution along the cochlea which can lead to pitch reversals across the cochlea and deviations from a correct tonotopic map. However, the VTP is specifically designed to provide a symmetrical distribution and therefore successfully maintains tonotopic organization.

We conclude that the VTP is likely to be a good stimulation mode choice for a strategy providing both current steering and focusing. 

Please take a read of the paper!