THE EXTENSION OF A LIGHT INFANTRY FOOT SOLDIER'S HEARING INTO THE ULTRASONIC

THE ABILITY OF THE INFANTRY FOOT SOLDIER TO DETECT ENEMY FOOT SOLDIERS WOULD BE HEIGHTENED BY THE EXTENSION OF HIS HEARING INTO THE ULTRASONIC REGION OF THE ACOUSTIC SPECTRUM. RECENT RESULTS INDICATE THAT ACTIVITIES SUCH AS WALKING OR CRAWLING THROUGH GRASS OR SAND, OR RUBBING CLOTHING OR SKIN TOGETHER EMIT SIGNIFICANT ULTRASONIC SIGNATURES IN THE 40 KHZ REGION OF THE ACOUSTIC SPECTRUM WHILE GIVING OFF MINIMAL AUDIO SIGNALS. A SMALL, RUGGED, ULTRASONIC DETECTION SYSTEM WHICH ACTED AS A NATURAL EXTENSION OF A SOLDIER'S HEARING WOULD ENHANCE HIS ABLITY TO DETECT ENEMY SOLDIERS. IT IS PROPOSED THAT THE ABOVE CONCEPT BE DEMONSTRATED BY DESIGNING AND FABRICATING A TEST BED SYSTEM WHICH WILL DETECT ULTRASONICS, MIX THE DETECTED SIGNAL DOWN TO THE AUDIO FREQUENCIES, AND DRIVE A SET OF SPEAKERS TO ALLOW A PERSON TO HEAR NATURALLY IN THE ULTRASONICS. THE PRIMARY TECHNICAL TASK OF THE DEVELOPMENT IS DESIGN OF A TRANSDUCER SYSTEM, INCLUDING FOCUSING ELEMENTS AND A ELETRONIC SUMMING NETWORK, WHICH WILL MIMIC THE DIRECTIONALITY AND RELATIVE SENSITIVITY OF THE HUMAN EARS SO THAT THE SOLDIER CAN LOCATE AN ULTRASONIC SOURCE AS IF HE WERE HEARING IT IN THE AUDIO ACOUSTIC RANGE. ANTICIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONSULTRASONIC LEAK DETECTORS ALREADY EXIST ON THE MARKET BUT ARE BULKYHAND-HELD UNITS. THE INCORPORATION OF THIS TECHNOLOGY INTO HEADGEAR WITH NATURAL DIRECTIONALITY WOULD PROVIDE AN INEXPENSIVE AND MINIATUREHEARING EXTENSION SYSTEM WHICH COULD OPERATE WITH LITTLE OR NO TRAINING. IT SHOULD PROVE USEFUL IN USING PERSONNEL TO LOCATE HIDDEN FUGITIVES, ANIMALS IN BRUSH AND FIELDS, LEAKS, VARIOUS MECHANICAL PROBLEMS, AND ANY OTHER SOURCE OF ULTRASONICS. IT WOULD NOT REPLACE THE EXISTING LEAK DETECTORS BUT WOULD SUPPLEMENT THEM.