Fuente: Wipo "Sensorization" A wearable brain activity monitor with electromagnetic sensors can be embodied in an ear-worn device. A first portion of the device can span a portion of the lateral perimeter of a person's ear and a second portion of the device can be inserted into the person's ear canal. In an example, the first portion can loop around 25% to 75% of the lateral perimeter of the person's ear.