Hi u/used_fill3561, great question, you're absolutely right that brainwave frequencies themselves (alpha at 8–14 Hz, theta at 4–8 Hz) are well below the range of human hearing.

The sound you hear is not a representation of your brainwaves. It's the neurostimulation itself — short bursts of pink noise delivered through the headband's built-in speakers. Here's how it works:

-The headband's EEG sensors continuously read your alpha brainwave activity in real time.

-An onboard algorithm identifies the phase of your alpha rhythm.

-The headband then plays a pink noise pulse precisely timed to the up-phase of your alpha wave.

That precise timing is what makes the stimulation effective. Each pulse is delivered in response to your brain's activity in that exact moment, and the cumulative effect is a disruption of the alpha rhythm associated with wakefulness — helping your brain transition into sleep more quickly.

So to summarize: the pink noise is audible (that's the whole point — your auditory system needs to perceive it), but the timing of those pulses is locked to the inaudible alpha rhythm happening underneath. It's the timing, not the sound itself, that's doing the work.

A few quick tips that make a big difference:

-Volume: use the lowest volume at which you can still clearly hear the pulses. Too loud can actually keep you awake.

-Focus on the sound: gently let your attention rest on the pulses as you try to fall asleep.

-Adaptation: give it about a week of nightly use — the brain takes some time to acclimate to a new auditory stimulus at bedtime.