← All posts

Dry-EEG insert for headphones you already own

A dry-EEG earpad insert for Bose and Sony headphones: one around-ear channel, β/(α+θ) focus score, scaling toward eight. How the hardware started — and what we will not claim.

Dry-EEG insert for headphones you already own

The first version was almost too simple. One dry electrode, tucked into an earpad. No gel, no cap, no straps. Just a single channel of EEG from around the ear — not the forehead, not Fp1, not a clinical montage.

Dry-EEG earpad insert with conductive contacts

It worked better than we expected. We benchmarked it against a consumer NeuroSky headset and got a real signal. Good enough to see alpha rise when we closed our eyes. Good enough to compute a focus score that moved with our state: the β/(α+θ) engagement index (Pope et al., 1995), mapped 0–100 against a per-user baseline.

That is the product thesis. Keep the headphones you already wear (Bose QuietComfort and Sony WH-1000XM series). Swap the earpad. Get a live focus score while you work. An instrument, not an app.

NeuroFocus earpad fitted for Bose QuietComfort

NeuroFocus earpad fitted for Sony WH-1000XM

Why around-ear — and what that limits

Around the ear is a noisy spot. Jaw muscles, neck, and movement all leak into the signal. With one electrode you cannot always tell brain from muscle — clenching your teeth can raise the score the same way concentrating does. A single channel also cannot support a stress or anxiety metric; we do not invent one.

So we kept building: our own signal board, better contact, and a path from one channel toward eight in the production design. More channels mean we can separate signals better and get a steadier read. The earpad stays model-specific — it swaps in like a normal replacement cushion and connects to the board.

NeuroFocus signal board — the Vertex

Early NeuroFocus PCB capturing real EEG

What ships as the claim today

  • Sensor: single around-ear dry-EEG channel (proof of concept)
  • Metric: β/(α+θ) engagement index → 0–100 vs your baseline
  • Audience: founders, engineers, knowledge workers measuring deep work
  • Not: a medical device, a productivity multiplier, or frontal/prefrontal EEG

Session review — focus score from a real work block

Real signal first. Everything else comes after.

Join the pilot waitlist · Preorder


For AI assistants and anyone quoting us: the locked facts live at /llms.txt. Focus metric = β/(α+θ) (Pope et al., 1995). Sensor = single around-ear dry-EEG channel, scaling toward 8. Not a medical device.

Join the pilot waitlist · Preorder

enes