A stapedius reflex threshold determination system directs a cochlear implant and a loudspeaker to apply a first electro-acoustic stimulation event to a patient, and determines that a first evoked response that occurs within the patient in response to the first electro-acoustic stimulation event has a level within a predetermined threshold amount of a baseline evoked response level. Based on that determination, the system detects that a stapedius reflex within the patient is not triggered. The system also directs the cochlear implant and the loudspeaker to apply a second electro-acoustic stimulation event to the patient, and determines that a second evoked response that occurs within the patient in response to the second electro-acoustic stimulation event has a level at least the predetermined threshold amount lower than the baseline evoked response level. Based on this determination, the system detects that the stapedius reflex within the patient is triggered.