After recording the voice pattern I am trying to re-open the file and compare it to an incoming voice pattern
You know that will not work, because even if you record exactly the same sound played back into the microphone you get a different set of numbers because the sample clock is not going to be exactly the same phase with respect to the sound as it was before.
I tried using the sound sensor module, but the maximum distance is only 1 foot,
You need one with more gain, but better would be a module with an AGC amplifier ( Automatic Gain Control ) something like this may help
I also tried using a PC microphone going through an OP Amp non-inverting amplifier (741)
The 741 was introduced in the early 1970s it requires +/- 12V supply. Their are plenty of much better amplifiers around that give close to rail to rail performance with a 5V rail.