Nowadays, three kinds of theories still discuss the nature of speech units: auditory theories (Diehl, Lotto, and Holt 2004), motor theories (Galantucci, Fowler, and Turvey 2006) and perceptuo-motor theories (Schwartz et al. 2012). Briefly, supporters of the auditory (resp. motor, perceptuo-motor) theories claim that speech units are represented in the brain by auditory (resp. motor, perceptuo-m...