Changes in psychophysical parameters during the first month of programming the nucleus contour and contour advance...

This retrospective study evaluated the psychophysical parameters of 29 postlingually deafened adults who had received a Nucleus Contour or Contour Advance implant during the first month of fitting in order to determine how many sessions were required to obtain a stable implant MAP. The T-levels did not differ significantly across the five fitting sessions, but the C-levels as well as the dynamic range showed an increase up to the fourth session. For all psychophysical parameters the basal, medial and apical portion of the electrode array differed significantly across sessions. Subjects with a Nucleus Contour implant had higher comfortable levels than subjects with a Contour Advance implant. The duration of deafness, presence of preoperative tinnitus, aetiology, frequency of fitting, stimulus rate and number of active channels did not significantly influence the psychophysical levels. These results suggested that four fitting sessions within the first three weeks after switch on should initially suffice and the fifth session could be planned beyond one month.