An exemplary fitting system 1) directs, during a fitting session, an EAS system to concurrently apply acoustic stimulation to a patient by way of a loudspeaker and electrical stimulation to the patient by way of an electrode located within a cochlea of the patient, 2) determines an interactive effect that the electrical stimulation has on the acoustic stimulation, 3) directs, if the determined interactive effect is suppressive, the EAS system to use, during a stimulation session, a first stimulation strategy that steers a current field produced by stimulation of the electrode away from intracochlear acoustic responders within the patient that are associated with the acoustic stimulation, and 4) directs, if the determined interactive effect is enhancing, the EAS system to use, during the stimulation session, a second stimulation strategy that steers the current field produced by the stimulation of the electrode towards the intracochlear acoustic responders.
