What was found
IN CRUISE FLIGHT AROUND 18 MINUTE AWAY FROM SYRACUSE, I RECEIVED A ROTOR RPM LOW AURAL ALERT AND CONFIRMED THAT BOTH MY NR AND #2 ENGINE N2 WERE BLEEDING QUICKLY TO ZERO. NO CHANGE IN AIRCRAFT PERFORMANCE, SOUND, OR HANDLING CHARACTERISTICS. I LOWERED THE COLLECTIVE, CHOSE A SAFE PLACE TO LAND AND CHOSE TO KEEP THE AIRCRAFT AT AN ATTITUDE THAT WOULD ALLOW MY NR TO BE HIGH JUST IN CASE MY ASSESMENT OF THE SITUATION WAS INCORRECT. UPON MECHANIC RESPONDING TO SCENE AND SOME MENIAL MAINTENANCE WE PERFORMED TESTING ON TRIPLE TACH PER THE REQUIRED MANUAL AND IT TESTED FINE. PERFORMED NORMAL GROUND RUN AND TESTED AIRCRAFT AGAIN. NO ISSUES. RETURNED TO SERVICE AND FLEW BACK TO BASE.