Fig. 1

a Thermal map of the head showing temperature differences. Written consent was obtained for the publication was of this photograph. b A prototype of the Tingle device, which uses an array of four 1-pixel sensors with different fields of view, a proximity sensor, and two IMU sensors. c Sample datastream in the Tingle application interface as the user approaches the mouth and hovers around various parts of the head. The top four signals are temperature readings from the four thermopiles, followed by the two IMU sensors, then the proximity sensor in blue. d LSTM network-based AUROC value distribution for the Tingle per target location on the head. e Confusion matrices for each location on the head with median values of classifier accuracy across participants