Strange Non Audible effect while pulsing a monofilar coil

[Peterae]

Many who have followed my work with nS phase delayed pulses using a monofilar coil will know about strange audible sounds picked up by electret microphones that are nearby to the test rig.

I am starting this thread because this needs explaining as it is currently an unexplained effect.

The strange noises have occurred many times over many videoed experiments, the setups have used different coils and different controllers, the only common thing is the phase delayed pulses, so the effect is produced by 2 fast ns pulses that are a delayed time apart, in some videos the laptop recorded the video on it's built in cam and was about  1 foot away from the setup yet the internal mike still picked up the strange noises easily.

The  Explosions video is probably best, it also has all the varying noises as well, the explosions are audible to my ears but all the varying tones are not.

I am pretty confident that the explosion are more than audible to my ears they are also picked up by the mike in this other form as are the strange noises my ears dont pick up.

Because the electret microphone is a capactive device then something must be causing this capacitance to be altering.

Explosion's video try after 1:00 for the strange noises and explosions.

Now this video is a strange one, it's exactly the same test as above and the audio should be the same, my ears could hear explosions occasionally only, but with this test i put the microphone slightly closer than the last test, but this time the sound is completely washed out with strange noises, it's as if i am receiving every radio station at once but using a microphone instead of a radio receiver.

I will probably add more videos when i get more time.