A hearing aid malfunction detection unit

A system is described, the Hearing Aid Malfunction Detection Unit (HAMDU), that electrically checks for proper operation of several aspects of hearing aid function. HAMDU is a miniature, add-on device which performs a check of hearing aid operation about every half hour, and which indicates malfunction by means of a highly visible, electrically tripped indicator. Functions checked include battery voltage, gain, distortion and noise, and continuity of the receiver cord. In addition, the indicator will be tripped if the hearing aid is turned off. HAMDU is small, low in cost, can be adapted to most body aids, and has no effect on hearing aid performance. The primary features of the system are that the hearing aid is checked periodically throughout its use, and the aid does not have to be removed from the wearer. The unit is designed specifically for body type hearing aids worn by children.