I am not sure if I can hear binaural beats. I tried a few of them in the past and always found them… mm what that word… like “metal rubbing on other metal” sounds which I don’t like and felt randomized. They don’t work for me. I am not sure if my hearing aids have something to do with it. Hearing aids does modify the sounds from the microphone and amplifies & output various range to get closer to “normal hearing level” to the ear. So, I don’t know if my hearing aids is outputting the binaural sounds correctly as it is intended to.
It is hard to find sound generators that would produce rhythmic beats rather than randomizing few beats here and there. Something like “beeee boop beeee boop beeee boop” or “swish bah swish bah swish bah” beats is what I prefer. My partner always looks at me funny everything I dance when my top-loader washing machine is on because it always produces simple rhythmic beats. Same for my dishwasher sounds.
Super interesting, thank you. 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.
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. 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.
Max Richter's "Sleep" is a recent artistic implementation of these, where different ones are used as a backing track throughout. 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.
Rare opportunity for the question to be on topic so had to ask, thank you!
It is more likely it is the hearing aids EQs are changing the sounds. Hearing aids is basically a computer in a tiny form, that why they are $2,000 to $6,000 USD each. Every hearing aids (each side of the ear) have a customized EQ for each wearer, it is conform to their hearing ability to pick up sounds. For myself, I can hear up to 2MHz and only audible at 100 dB with hearing aids. I can’t hear past 2.5Mhz range but I can feel the vibration in my cochlea. That helps me to know they are speaking outside of my frequency range. I often have issues understanding people who is using tonal language like East Asian languages, it sounds like they are speaking from a Walkman CD with skipping every 5 seconds.
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.
So, well into the speculative here, if binaural beats are indeed a real thing, e.g. that by offsetting a tone between two ears and frequencies it produces a third epiphenomanal artifact that is not explicitly "heard," but processed outside the range of what the ear can distinguish by the brain, it does imply we could take any sound and then modulate it so that it appeared or was realized in this meta effect range where the brain automatically processes it.
If binaural beats are not real, then there's a lot of speculative woo that automatically gets debunked. But if they are real, and there were a way to take a frequency or sound, and modulate it so that the effect could be processed by the brain as an artifact of its own processing and not as the actual physical "sound," that could be interesting. Maybe the way hearing aids EQ sounds also shifts frequencies and folds them into the range the listener can physically hear already. If there were a meta sound that binaural beats in effect claim to be, there would also be an FFT that would take a given sound input and transform it through stereo headphones to produce it at the frequency one could "hear" as an artifact of the brain reconstructing it.
I'm well into the territory of "dare to be stupid" speculation here, but the premise of creating a binaural beat to create this super-audible artifact, then modulating the artifact effect to transmit the information would be pretty interesting (probably even an ffmpeg one liner). I like cuban cigars and american whiskey if someone reading this becomes a billionare as a result of implementing it, but if it doesn't make a difference, there's a whole subculture of binaural beat internet woo that needs to know it isn't a thing. :)
It is hard to find sound generators that would produce rhythmic beats rather than randomizing few beats here and there. Something like “beeee boop beeee boop beeee boop” or “swish bah swish bah swish bah” beats is what I prefer. My partner always looks at me funny everything I dance when my top-loader washing machine is on because it always produces simple rhythmic beats. Same for my dishwasher sounds.