The present application discloses a hearing prosthesis configured to alert a user of the presence of sound while operating in a sound awareness mode of operation. When a user of the hearing aid removes the external sound processor and microphone, traditionally, a hearing prosthesis does not produce any audio stimulus. Here, the systems and methods will alert a user to sounds in his or her environment when the external sound processor and microphone are decoupled from the internal components of the hearing prosthesis. In some embodiments, the hearing prosthesis may have an acoustic receiver that is implanted in the recipient. The implanted acoustic detector may be used to detect an aspect of a sound above a threshold level. The threshold may be chosen so the detected sound is a loud sound such as a fire alarm.