When {HEAD ~ the first number} of {TAIL ~ shock events} exceeds an upper event threshold, a control signal is adjusted in order to adjust a frequency spectrum of noise affecting the shock detector 
of
When { HEAD ~ the first number } of { TAIL ~ shock events } exceeds an upper event threshold , a control signal is adjusted in order to adjust a frequency spectrum of noise affecting the shock detector
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH