An implantable myocardial stimulation lead comprises a lead body having a distal end and a proximal end, and an electrical connector carried by the proximal end of the lead body. A monitor circuit is provided for monitoring power characteristics relating to UV andor fluorescent lamp operation, such as the lamp supply voltage or the current traversing the lamp. The formulation has an excellent shelf-life in which caking and sedimentation are inhibited. From such information, a transfer function characterizing the sound producing system is generated.