ochen k. discusses a story bouncing around the interweb about the uses of sounds so high in frequency they can only be heard by subhuman life-forms, like dogs and teenagers.
He came up with the clever idea of recording a bunch of tones at increasing frequencies so you could listen in and figure out where your cutoff range is. I didn’t get a good idea of mine because I could hear:
- 15KHz clearly
- 16 not at all,
- 17 faintly but distinctly,
- 18 so faintly I don’t know if I was imagining it,
- 19 very clearly,
- 20 very clearly,
- 21 very faint but there,
- 22 very faint but there,
- 23 not at all,
- 24 just barely barely audible but there,
- 25 no way.
This weird pattern of frequencies suggests that the test isn’t that useful. One of the commenters pointed out that a high note may have a low harmonic within it, so some of the super high ones I heard, maybe I wasn’t hearing the actual frequency, just some piece of its harmonics. Also, they’re mp3s. Lossy compression. Heaven knows what that does to pure tones. You know how JPGs cause the most visible, nasty artifacts on very simple clean precise geometric forms? I would not be surprised if mp3 compression is an equally iffy proposition for very high pure synth tones.
This is via digg.