By Layal Liverpool
Tap tap tap
Alina Rosanova/Getty Images
Voice assistants can detect typing on nearby devices, which could potentially be used to work out what a person is writing on their phone from up to half a metre away.
Ilia Shumailov at the University of Cambridge and his colleagues built a machine learning system that could recognise the sound of tapping on a touchscreen and combined it with other artificial intelligence tools to determine what people were typing.
Shumailov and his team asked three volunteers to type randomly displayed 5-digit PIN codes or English words on a touchscreen device while audio was …