Implementing a psychophysical interface for the sound processor for electrical and acoustic research version 3 (SPEAR3)

Abstract

Current speech processing strategies use amplitude‐modulated fixed rate pulse trains to communicate information. Using acoustic models, researchers have recently demonstrated that variable stimulation rate strate‐ gies may provide an improvement of speech perception in noise and music perception [Nie et al., 2005; Stohl and Collins, 2006; Throckmorton et al. (2006) (in press)]. It has been hypothesized that successful implementation of these strategies will require psychophysics‐based tuning. An experimental interface is needed to implement such psychophysical experiments, and most interfaces provided by implant manufacturers do not provide the stimulus design flexibility necessary. HearWorks provides the SPEAR3 developmental sound processor, which is capable of dynamically updating the stimulation rate and offers bimodal and bilateral configurations. Assembly and Visual Basic code is included with the SPEAR3, but must be modified and expanded to implement dynamic stimulus presentation and graphical user interfaces for specific psychophysical tasks. Using data collected from Nucleus CI 24 implant users, we will demonstrate that the SPEAR3 may be used to implement general psychophysical experiments. The ability of the SPEAR3 speech processor to implement variable stimulation rates is critical to future psychophysical testing of variable stimulation rate processing strategies.