With the method of analysis demonstrated in part 2 of the subject title, and the requirement for accurate reproduction of the signal (presented in Salt Lake City) the hypothesis as to infrasound contributions is revised in light of further investigations with test subjects for both inaudible ILFN and audible LFN to 50 dB(A). The work ties in with the investigations into the startle reflex using wind turbines as the source of the acoustic trigger. The ramifications as to suitable criteria for the protection of the community are discussed.