Believe it or not, I’m not trying to impress you with my pitch. That wobbling you’re hearing is the result of a tuning discrepancy. It’s what happens when two sounds reach you a little out of step with each other, and in this case it’s because their pitches are a little different.
If we sample and loop them to get rid of any deviation, we can assign them each to a note and play them in a sustained manner. That’ll allow us to render the waveform and take a look at what’s going on. If the first note cycles at about 310 Hz, the second is probably around 315, and that creates a beating at about 5 per second.
This all becomes more clear once we line the waveforms up, put one on top of the other, and look at what happens as they intersect. Here you see the top wave pulling while the bottom’s pushing, and that means these two, for the moment, are out of phase. But if we travel about a fifth of a second downstream, you’ll find the problem corrects itself and then it repeats.
It’s evident in the final waveform and you’ll see this in everything from synthesis to tuning a guitar string, and you can share this with someone who belongs in a beat-kitchen class.
