Ear-EEG (in-ear and around-ear)

EEG recorded from electrodes placed in the ear canal, in the concha, or on a flexible grid wrapped around the outer ear. The appeal for real-world use is discretion and mechanical stability: the ear anchors the electrodes firmly, the geometry is nearly the same each time it is worn, and the device looks like an earbud rather than a cap, which matters enormously for all-day and social wear.

The trade-off is coverage. Ear electrodes sit far from most of cortex and record best the sources nearest to them — temporal-lobe activity, auditory responses, and volume-conducted rhythms — so many classical scalp patterns arrive attenuated or not at all. The strongest applications are therefore ones where a nearby or global signal suffices: sleep staging, auditory attention decoding, drowsiness and seizure monitoring, and long-duration ambulatory recording where a full cap is simply impractical.