This is a single-threaded asynchronous application. In all cases, the file is just being passed. To be honest, no, I'm not doing any sort of measuring other than listening for audible differences in the pauses between the prompts; the ones being chosen are picked randomly. The file size being different is a result of when I decided to stop the tests, since it's designed to run forever.
I understand why playing random wave files may not seem like the best documentation of the issue. I'll re-run this using tones generated by the DSP.