So, well into the speculative here, if binaural beats are indeed a real thing, e.g. Looking it up, 2khz is about C7 (c note at 7th octave), which most music is below, but you'd miss a lot of additional harmonics that could have context.

Rare opportunity for the question to be on topic so had to ask, thank you! I'm hacking around with reproducing them on a synth rig, but even then, the stuff written about them is mostly using pure sine waves, so even if you get interesting sound effects from other types of waves (saw, triangle, pulse, etc), there's not much in the way of empirical control.

Max Richter's 'Sleep' is a recent artistic implementation of these, where different ones are used as a backing track throughout. The tension between the tones does manifest as a kind of stimulation or subtle irritation, and higher frequencies could plausibly create an anxiety effect, like metal on metal you described. The beats are the artifact of directing two frequencies with a difference of only a few Hz, one per ear, and the 'beat,' phenomenon is a pulse we mentally feel as the result of the brain allegedly straining either to distinguish or consolidate the two tones from each ear as the same or separate. Indeed, if the hearing aid EQ'd the input to bring out things in the range of speech, the effect in most of the artistic binaural beats tracks could be suppressed, as the effect is caused by a very specific difference between tones sent to each ear.

Binaural beat only