Stereo to Mono wav in Python

First, what is the datatype of audiodata? I assume it's some fixed-width integer format and you therefore get overflow. If you convert it to a floating point format before processing, it will work fine:

audiodata = audiodata.astype(float)

Second, don't write your Python code element by element; vectorize it:

d = (audiodata[:,0] + audiodata[:,1]) / 2

or even better

d = audiodata.sum(axis=1) / 2

This will be vastly faster than the element-by-element loop you wrote.

turns out, all i had to change was

(right+left)/2

to

(right/2) + (left/2)