Wearable cardiac defibrillator (WCD) system sounding to bystanders in patient's own voice

A wearable cardiac defibrillator ("WCD") system may include a support structure that a patient can wear, an energy storage module that can store an electrical charge, and a discharge circuit that can discharge the electrical charge through the patient so as to shock him or her, while the patient is wearing the support structure. Embodiments may actively take into account bystanders, both to protect them from an inadvertent shock, and also to enlist their help. In some embodiments, the WCD system includes a speaker system and a memory. Prompts have been saved in advance in the patient's own voice, and stored in the memory. In case of an emergency, the prompts may be played by the speaker system in the patient's own voice, and heard by a bystander.