Comparing two dependent? groups

[matlabber]

Hi,

I have a mathematics/Matlab question. Suppose I have a speaker that serves as a sound source, and two IDENTICAL microphones to the left and right of this speaker. Suppose that each microphone collects data regarding the sound level of the speaker, and that there are over 3,000 data values for each of the microphones. How can I determine whether the differences in the data for the left and right microphone are due to randomness, or if there is an actual difference when placing a microphone to either the left or right of a speaker? I am not sure what method to use, and which function may correspond in Matlab.

Thank You!

 

[pbuk]

Are the data recorded (nearly) simultaneously, so that you can compare pairs? Or is the sound from the speaker white (or pink) noise so that you can make an assumption about the expected distribution of results?