What do we know about brain wave?

I don’t believe there is a link between brain waves and sound frequency. An EEG measures electrical impulses on the surface of the brain, and certain patterns are associated with certain pathologies. What that has to do with sound is anyone’s guess.

If you search Google Scholar for “brain wave” you will get 13,400 hits. You will have to be a little more specific than “what do we know about brain wave.”

Generally speaking, brain waves are rhythms of activity generated by summing together bursts of electrical activity, mostly from postsynaptic potentials, in individual neurons. They oscillate at frequencies between about one and 100+ hertz. Slower oscillations are associated with minimal consciousness (specifically, slow wave sleep) while the fastest oscillations are associated with states of heightened attention and focus.

The audible spectrum runs from about 16 to 20,000 hertz. I’m not sure what kind of relationship between brain waves and sound frequency you’re looking for. Can you be more specific about that as well?

Here’s the link

Sound (of a certain frequency) enters your ear. The conversion of sound waves to neural signals is accomplished in the inner ear, in the structure known as the cochlea. The various neural signals can be measured as brain waves. They are slightly different depending on the frequency of the sound. People with absolute pitch can even identify the key e.g. on a piano.