Do-able
Dear Dooch,
In reverse order,
- Yes, IMHO it's a worthy endeavour, definitely "worth bothering" about...
- There are various ways to approach this, with attendent change in $$$ and degree-of-manual-intervention required.
To start with, "storm sound modules" of various qualities are available from various suppliers. I'm thinking primarily of the ITTC modules http://www.ittproducts.com/products.html (scroll down to the "HQ500" module).
However, these units tend to not have any form of control output, so no way to control lighting from the sound module. Arguably yes, you could use a "lighting controller" and send the "play noise now" command to the ITTC module, but most "lighting controllers" with suitable capabilities are pretty $$$$.
(and besides which, I tend to think of sound as the "master controller" before I think of lighting or animation...)
Now, what say we want to upgrade the audio resolution (CD-spec), and add both trigger IN and control OUT capability? Well, check the DreamPlayer MK2 from Pricom. http://www.pricom.com/Trains/DreamPlayerMK2.shtml
I specifically note the MK2, as it is the most cost-effective of the range which includes "multi-random" mode. This mode effectively means that you can trigger "the thunder",
(whether via layout fascia button, person proximity detector, timed trigger, or other),
and the unit will randomly choose for up-to 4 different "thunder" sound files per "track". Point being, each time the thunder occurs, it'll be a different one, thus avoiding an oft-held complaint about triggerable "gag" SFX,
"...it always sounds the same..."
SO, we now have a CD-spec audio "thunder" generator triggering away on command,
what about the light(en)ing?
The Control Outputs of the MK2 can be configured for "pulse at start" (of audio playback),
so one way would be
- take the control output of the MK2
- configure for "pulse at start"
- connect to strobe light or similar "bright quick flashing light" circuit
and you're done 
"...But hold on..." I hear the cry, "...the visible lightening should happen _before_ the audible thunder, not right at the same time, yes?"
Yes, yes it should, unless you're standing right under the thunderhead
And by tweaking the sound files to have a small portion of silence on the head or start of them,
we can effectively "delay" the audible thunder, relative to the "pulse on start" lighting control signal occurance... (Bonus points, by varyng the ammount of silence on the head of the 4 "multi-random" WAV audio files, we can easily and automatically simulate lightening strikes occuring at different distances from the viewer/listener ).
Hmm, something is still not quite right here, the thunder _sound_ is almost infinitely variable, but the lightening is still an all-too-consistent "strobe" flash. Is there any way we can actually control the behaviour/appearance/duration/variable-brightness-over-time of the "lightening flash"?
Um, there actually is, _IF_ you're willing to think laterally. The DreamPlayer (and most any audio device with a truly decent analog audio output stage) can drive an LED directly. Yes, you can use _sound_ signals to directly-drive _lights_. In this instance, if we
- pan the thunder sounds to the LEFT hand channel of the WAV file
(The DreamPlayer is a Stereo device, and handles Stereo WAV files)
- put some _NOT_ intended to actually be listened-to "clicks and pops" audio in the RIGHT hand channel of the WAV file
- wire the 3.5mm minijack stereo LEFT output of the Dreamplayer to a suitable speaker rig
(Remember, the LEFT channel is playing "meant to be listened to" thunder audio,
and any thunder worth it's salt will need a subwoofer to really give it some Kick!)
- wire the 3.5mm minijack RIGHT output to a pair of back-to-back "Cool White" and maybe "Ultra Blue" high-brightness LEDs
and you now have a "thunder and lightening" rig,
- with CD-spec sound capability
- the lightening - and then the thunder - in correct relative time sequence
- and where both the visible lightening and the audible thunder are easily tweakable/adjustable/programmable within a simply GUI audio editing application (the FREE audio editing app Audacity will do the job)...
That's pretty potent, and not all that difficult or expensive to deploy. At the risk of dissing the DreamPlayer, the same "thunder on the Left, Lightening on the Right" technique could just as easily be used with a cheapo MP3 player, as long as you were OK with loosing the "trigger on demand" trigger-input capability which is inherrently part of every DreamPlayer unit.
If you want to go furthur however, you're talking a significant step up in ammount-of-gear-required, and potential cost. I know that Pricom are working on lighting-control units which will mate up with their DreamPlayer PRO, and communicate with each other over "PNET". The JMRI and OpenLCB/NMRAnet teams are also looking at what's involved with integrating "layout room lighting control" and LEDs with their systems, so there's another possible way-forward...
...and of course, if $$$$ is no object, there are plenty of Pro Lighting/Concert/Theatre control systems based on DMX and ShowControl protocols, which could easily achieve "...a little thunder and lightening show..."...
(Theatre, DisneyWorld, and most any concert you might care to name would find the above "fall-off-a-log" easy... ).
SO, there's some thoughts, hope it helps!
Happy Modelling,
Aim to Improve,
Prof Klyzlr
PS if the "thunder on LEFT, Lightening on RIGHT" concept sounds good, but you cannot bring yourself to loose the STEREO capability of the playback device,
(you're monopolising the RH channel for not-intended-for-human-ears "lighting/utility signal)),
then you may be interested in the idea of a "color organ". Color Organs recieve an audio signal, which includes super-audible control tones. (EG 20kHz super high frequency tone, above most average adult human's range of frequency response). The color organ allows the "audible audio" to pass thru to the speakers, but uses the 20kHz tone as a "control" for a seperate physical output, in this case, a "lightening" output.
(More 20kHz tone = brighter color-organ output,
"clicking" or 'spitting" morse-code style 20kHz tone = "lightening flashing" output from the color organ...)
The guys over on the LayoutSound Yahoogroup have been kicking around all of the above ideas for a number of years now, so if you'd like to discuss furthur, I'd reccomend you give them a shout...
