Understanding common collector amplfier for a piezoelectric microphone
I found that the amplifier is arranged as a Common Collector


That would be incorrect - it's a common emitter. Connect "pad 4" to ground and use an external pull-up resistor from "out" to some supply voltage (maybe 6 volts to 12 volts) and that junction labelled "out" is an output that feeds into an amplifier. 

The value of the pull-up resistor sets the gain - if it were 1 kohm then the gain would be ten - the ratio of collector pull-up resistor to emitter resistor (100 ohm) sets the gain. The 470R is just there to limit too much current into the circuit should you choose an external pull-up that is too low.