I have tinnitus. It manifests as a sharp sinewave as well. For a week however, the frequency of the sinewave dropped. It sounded exactly how a medium frequency sinewave from my phone, at around maybe 500 mhz( actually its hz) , and it could go down to around 400. It was just for that week, and then it stopped.
Your comment reminded me of that, and I thought it's an interesting enough story
Randomness (even the computer's pseudorandom) is really amazing. Perlin noise, Sierpinski triangles traced through random walking, etc... Lots of things can be done with random sequences.