At the conclusion of their routine clinic visit, each patient will have his or her pacemaker attached to the appropriate proprietary interrogation system for their pacemaker device. We will then monitor the pacemaker/ICD system while placing a series of portable music devices at various distances from the pacemaker/ICD system: (1) 2cm, (2) 30cm, (3) 100cm. At each distance the pacemaker will be re-interrogated for changes in pacemaker sensing thresholds, pacing thresholds, telemetry interference or pacemaker inhibition. At the end of the testing process, the devices will be removed from near the patient and the device will be interrogated again to assure that the device is at the appropriate clinical settings.