A system comprising: a memory storing instructions; a processor communicatively coupled to the memory and configured to execute the instructions to: direct an acoustic stimulation generator to apply acoustic stimulation having a stimulus frequency to a recipient of a cochlear implant during an insertion procedure in which an electrode lead (110, 600, 700) communicatively coupled to the cochlear implant is inserted into a cochlea (200, 602, 714) of the recipient; direct the cochlear implant to use an electrode (112, 604, 710) disposed on the electrode lead to record an evoked response signal during the insertion procedure, the evoked response signal representing amplitudes of a plurality of evoked responses that occur within the recipient in response to the acoustic stimulation applied to the recipient; and incrementally step, as the electrode lead is inserted into the cochlea, the stimulus frequency through a sequence of decreasingly lower values starting with an initial value and ending with a final value lower than the initial value, wherein: the processor is further configured to execute the instructions to determine, while the stimulus frequency has the initial value, that the electrode passes a characteristic frequency location within the cochlea and corresponding to the initial value; and the incremental stepping of the stimulus frequency comprises decreasing, in response to the determination that the electrode passes the characteristic frequency location, the stimulus frequency from the initial value to a next lower value included in the sequence of decreasingly lower values. a memory storing instructions; a processor communicatively coupled to the memory and configured to execute the instructions to: direct an acoustic stimulation generator to apply acoustic stimulation having a stimulus frequency to a recipient of a cochlear implant during an insertion procedure in which an electrode lead (110, 600, 700) communicatively coupled to the cochlear implant is inserted into a cochlea (200, 602, 714) of the recipient; direct the cochlear implant to use an electrode (112, 604, 710) disposed on the electrode lead to record an evoked response signal during the insertion procedure, the evoked response signal representing amplitudes of a plurality of evoked responses that occur within the recipient in response to the acoustic stimulation applied to the recipient; and incrementally step, as the electrode lead is inserted into the cochlea, the stimulus frequency through a sequence of decreasingly lower values starting with an initial value and ending with a final value lower than the initial value, wherein: the processor is further configured to execute the instructions to determine, while the stimulus frequency has the initial value, that the electrode passes a characteristic frequency location within the cochlea and corresponding to the initial value; and the incremental stepping of the stimulus frequency comprises decreasing, in response to the determination that the electrode passes the characteristic frequency location, the stimulus frequency from the initial value to a next lower value included in the sequence of decreasingly lower values. direct an acoustic stimulation generator to apply acoustic stimulation having a stimulus frequency to a recipient of a cochlear implant during an insertion procedure in which an electrode lead (110, 600, 700) communicatively coupled to the cochlear implant is inserted into a cochlea (200, 602, 714) of the recipient; direct the cochlear implant to use an electrode (112, 604, 710) disposed on the electrode lead to record an evoked response signal during the insertion procedure, the evoked response signal representing amplitudes of a plurality of evoked responses that occur within the recipient in response to the acoustic stimulation applied to the recipient; and incrementally step, as the electrode lead is inserted into the cochlea, the stimulus frequency through a sequence of decreasingly lower values starting with an initial value and ending with a final value lower than the initial value, wherein: the processor is further configured to execute the instructions to determine, while the stimulus frequency has the initial value, that the electrode passes a characteristic frequency location within the cochlea and corresponding to the initial value; and the incremental stepping of the stimulus frequency comprises decreasing, in response to the determination that the electrode passes the characteristic frequency location, the stimulus frequency from the initial value to a next lower value included in the sequence of decreasingly lower values. the processor is further configured to execute the instructions to determine, while the stimulus frequency has the initial value, that the electrode passes a characteristic frequency location within the cochlea and corresponding to the initial value; and the incremental stepping of the stimulus frequency comprises decreasing, in response to the determination that the electrode passes the characteristic frequency location, the stimulus frequency from the initial value to a next lower value included in the sequence of decreasingly lower values.