Camera Flash Charge Circuit Sound Simulator

[zcomputerwiz]

I'd like to build something to simulate the sound from noisy transformers in old flash capacitor charging circuits for a prop.

Looking at a generic flash capacitor charge circuit, could I replace the transformer and high voltage capacitor with a speaker and large low voltage capacitor with a couple more transistors for feedback?
I think I'd only need a speaker, 3 transistors, one diode, a large capacitor and two small capacitors with the right resistors to make something that oscillates faster as the charge in the large capacitor builds, but I don't know how to find the values required for the capacitors and resistors to get the sound I want.

Anyone have suggestions for reading material to figure this out on my own, or could walk me through it here?

[I wanted a rude username]

Not sure the exact circuit you have in mind, but driving the speaker might dissipate the power that would otherwise go into charging the capacitor.

Since it's for a prop, maybe just use a Raspberry Pi as a tone generator?

[Circlotron]

If you need a bit of volume, get an actual flash and place a pickup coil near the transformer and feed this to an amplifier and loudspeaker.

[themadhippy]

use  one of those greeting card chips and record the actual sound, add a small chip amp
 for a bit more  umph