We evaluate the effects of multisensory training on letters, including sonification of graphic symbols. We used “spatial sonification” where letter handwriting movements recorded in a two dimensional plan, vertical and horizontal, are systematically assigned to two acoustic features, spectral composition for the horizontal axis and frequency for the vertical axis. Forty-six kindergarten children were recruited. They were randomly assigned to three multisensory training groups: with sonification (Son) of letters, with a melody unrelated to the shape of the letters (Mel) and without any sound (Sil). We observed a significant effect of training, with the Son group performing better than the other groups in the reading and spelling tasks. We also observed a modification of two kinematic cues (time and in-air time) during handwriting, also in the Son group. We conclude that letter sonification could act as a binder between the visual and auditory dimensions of the letter. The processes underlying this benefit are discussed in the light of the Act-In model, a cognition memory model.