Sound trigger for high speed flash photography

I did not design the following circuit:

http://i.stack.imgur.com/XJa21.png

I did not follow it to specification either.  For this circuit, I bought an electret condenser microphone ($1.50), an LM324 op-amp ($0.70, instead of the LM741), and 0.47 uF polarized capacitors ($0.20 each).  Also, instead of the 100 KOhm resistor, I used a 1 MOhm potentiometer ($0.70, set at 1 MOhm for higher amplication).  Instead of the 10 KOhm resistors, I used 6.8 KOhm resistors.  Instead of the 2.2 KOhm resistor, I used two 1 KOhm resistors.  The output of the circuit is then fed to the base of a PN2222A transistor that will trigger the flash gun.  The purpose of the circuit above is to amplify the voltage signal created by the electret microphone.

Well, my first attempt was not very successful.  Yes, the electret microphone seems to work.  (I read somewhere it generates a range of only 14 mV, hence amplification required.)  However, the circuit is not sensitive enough.  I am able to trigger the flash gun by clapping my hands only.  Snapping my fingers does not produce strong enough of a voltage to trigger the flash gun.  A water drop will produce a lot softer sound, so there is no way that this circuit will work for me.  Well, I gotta do some more thinking now....  I am also thinking whether I should just buy an electret audio amplifier from eBay for $4.25, although, I do not know if they are sensitive enough either.

Reference:

• The circuit above came from http://electronics.stackexchange.com/questions/16529/why-is-microphone-opamp-arduino-circuit-not-working
• Parts of an electret microphone
• How to use an electret microphone
• Basic powering information on electret microphones