PI passed away. Ending grant and closing lab.

In this study, the investigators will study one of the basic biophysical properties of the auditory nerve, charge integration, behaviorally (detection threshold versus phase duration functions). The investigators will compare charge integration in two subject groups: congenitally deafened and deafened at a later age in life. The investigators will then examine if behaviorally estimated neural excitation patterns differ between short phase duration and long phase duration stimulation. Lastly, The investigators will measure if speech recognition improves with using long phase duration stimulation, relative to using the standard default short phase duration stimulation. The primary endpoint of the study is speech recognition, and the secondary endpoints are the steepness of the detection threshold versus phase duration functions, and the width of psychophysically estimated neural excitation.

Inclusion Criteria:

• Cochlear Nucleus cochlear implant users or Advanced Bionics cochlear implant users
• Native speakers of English
• Early onset of deafness (< 3 years of age); no requirement for age at implantation
• Late onset of deafness (> 3 years of age); matched in duration of deafness to the early onset group
• Has had device experience for at least one year
• Can be child or adult at the time of enrollment

Exclusion Criteria:

• None

Children and adults with cochlear implants (Advanced Bionics and Cochlear Nucleus devices)