Ear-EEG

Ear-EEG records brain activity from electrodes placed in or around the ear canal and concha, typically embedded in a custom or generic earpiece. The attraction is discretion and stability: an in-ear device is unobtrusive, self-inserted, and mechanically anchored, making it a candidate for all-day monitoring of sleep, alertness, seizures, and auditory-attention BCIs.

The tradeoff is coverage and amplitude. The ear samples a small, fixed region close to temporal cortex, so signals from distant sources (for example occipital or frontal) are weak, and the short inter-electrode distances yield small potential differences with poorer low-frequency performance. Ear-EEG therefore excels for paradigms with strong, nearby, or well-characterised sources such as auditory steady-state responses, certain sleep stages, and alpha modulation, rather than as a general-purpose replacement for full-scalp montages.