I have a deaf employee. Very good young man. His job entails him working alone in buildings sometimes in the basements. There is been an occasion that the fire alarm has went off and due to him being inside of a large air conditioning unit working he could not see the strobe lights nor hear the audible alarms. is there a device made that my company can purchase that he can set beside one of the audible alarms and he wear some sort of sensor that will flash and vibrate if it senses an alarm? I have looked everywhere and have found nothing. This equipment has got to be robust and easily portable. Please help me.