Correlation between intra-operative high rate neural response telemetry measurements and behaviourally obtained threshold and comfort levels in patients using Nucleus 24 cochlear implants

Abstract

The correlation between high rate 250 Hz intra-operative threshold neural response telemetry (t-NRT) with behaviourally obtained psychophysical threshold (T) and comfort (C) levels of the most recent and stable maps of 90 consecutive cochlear implantees using Cochlear Implant 24 Mini (CI 24 M) (M: F - 26:19), aged between two and 60 years with a mean age of 9.61 +/-12.07, was studied. The intra-operative t-NRT levels were seen to fall between the T and C levels and a good correlation was found between t-NRT and T and C levels (r = 0.327 at p < 0.005 for the T level and r = 0.648 at p < 0.001 for C level vs intra-operative t-NRT). The present study supports the view that 250 Hz NRT is not only a valuable clinical tool in evaluating the integrity of the implant and status of peripheral auditory nerves but can be used in programming the speech processor for young and difficult recipients, as has been previously shown using low rate NRT.