Re: Close lightning strike and strange tick (fwd)

["High Voltage list" <hvlist@xxxxxxxxxx>]

Original poster: Steven Roys <sroys@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Sun, 08 Jul 2007 18:21:58 -0500
From: Bert Hickman <bert.hickman@xxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Close lightning strike and strange tick (fwd)

High Voltage list wrote:
> Original poster: Steven Roys <sroys@xxxxxxxxxx>
> 
> 
> 
> ---------- Forwarded message ----------
> Date: Sun, 8 Jul 2007 11:14:06 -0600 (MDT)
> From: Chip Atkinson <chip@xxxxxxxxxx>
> To: hvlist@xxxxxxxxxx
> Subject: Close lightning strike and strange tick
> 
> Greetings,
> 
> I was out walking yesterday with my gf and experienced a really strange
> phenomenon. Lightning struck fairly close to where I was so that the
> thunderclap was about .1 second after the flash.  The amount of time
> separating the flash and boom was long enough that you could notice a
> delay but not really any longer.  My .1 second estimate is based on the
> fastest I could start and stop a stop watch.
> 
> But anyway, the most interesting thing was that simultaneous with the
> flash was a weird "tick" sound.  It was kind of like a "plasticky" tick
> like you flipped a plastic dinner plate with your fingernail.  I know 
> I wasn't imagining anything since my girlfriend heard the sound too.  She
> also felt that it was pretty much simultaneous with the flash.
> 
> Any ideas anyone?
> 
> Thanks in advance.
> 
> Chip
> 

Hi Chip,

I had the same experience several years ago, under very similar 
circumstances. I heard it as a "tick" or "click", very similar to your 
description. It was a quick, short click, but considerably "duller" than 
  the sharp snap of an electric spark, and it was simultaneous with the 
first flash.

One possibility is that you an incomplete upward leader from a very 
nearby object. However, I don't think this was the case, since the sound 
was not a sharp, spark-like crack. Another possibility is that, with the 
main discharge, the nearby electrical field suddenly changed. This might 
cause a sudden movement of leaves on trees, blades of grass, etc. 
However, I wouldn't expect the noise to be a brief "tick" since the area 
affected by the E-field change would be fairly large and the sound more 
distributed.

Another possibility, and the one I suspect, is that you actually 
detected the electromagnetic impulse from the lightning strike itself. 
If so, it may be related to a phenomenon known as the "microwave 
auditory phenomenon" (also known as the "microwave hearing" or "Frey 
Effect"). This occurs when humans (and some animals) are subjected to 
short impulses of microwave radiation. The exact mechanism(s) are not 
completely understood. Some theories invoke thermal-acoustic pulse, 
which is induced within the water in your soft tissues and then detected 
by your inner ear. Other research implies that there may be more direct 
detection processes going on within the brain itself. For a pulsed 
microwave signal, the "sound" that is heard is a click coincident with 
the leading edge of the pulse. Changing the parameters of the pulse can 
change the sound, and audio modulated words can also be detected... 
sounding sort of like a Cylon (robot-like).

There is no doubt that the above effects are real and repeatable for 
microwave and radar pulses... perhaps for lightning RF impulses as well??

Bert
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