First ~2 seconds is basic audio. Then there's ~2 seconds with a 140hz sine wave to generate "noise." We sampled *just* the tone for our NR, then ran it on the ~2.5 seconds, and you can see what's *actually* happening. There's another ~2 seconds of basic, raw, recording to bookmark the hollow sound of your shitty NR attempt, and then finally the last ~1 second is both the test tone and raw audio both filtered out for that 140hz tone.