An adaptive place-pitch ranking procedure for use with a cochlear implant
or other neural stimulation system provides a systematic method for
quantifying the magnitude and direction of errors along the place-pitch
continuum. The method may be conducted and completed in a relatively
short period of time. In use, the implant user or listener is asked to
rank the percepts obtained after a sequential presentation of monopolar
stimulation pulses are applied to a selected spatially-defined electrode
pair. Should the patient's judgment of pitch order be correct for all
applied interrogations, then no further testing involving the tested
electrode pair (two electrode contacts) is undertaken. However, should
there be errors in the place-pitch ranking, which errors evidence
perceptual place-confusions, then a search is undertaken for the spread
of the perceptual confusion by separating the target channel and
competing channel by one electrode contact at a time. This search for the
spread of confusion continues until no errors are made in all directions.
Identified channels wherein pitch confusion exists may be deselected (not
used) during normal operation of the cochlear implant.