A wearable defibrillation system includes an output device and a motion sensor. The output device emits a sound or a vibration for the patient, who responds by deliberately tapping the system. The motion sensor registers the tapping, and interprets it as a reply from the patient. The reply can be that the patient is conscious, or convey data that the patient enters by tapping the right number of times, or that the patient wants attention, and so on. Since the patient does not need direct access to the wearable defibrillation system for tapping it, he or she can wear it under their other garments, which helps preserve their dignity and privacy.