Which parameters ore metrics can be used to differentiate two simple speach signals recorded using the following code?

I have used the following code to record and write speech signals

clc
clear all
close all
% Record the voice password for 3.55 seconds.
record = audiorecorder;
disp('===============Speak Password============')
recordblocking(record,3.5);
disp('===============End of Recording==========');

% Play back the recording.
play(record);

% Store data in an array.
audiodata = getaudiodata(record);

% Plot the waveform.
plot(audiodata);

filename = 'key_audio.wav';
audiowrite(filename, audiodata, record.SampleRate)

how to differentiate two speech signals recorded here