Tomatis discovered that the fetus can hear from four and a half months into pregnancy, and that he mainly listens to his mother’s voice. From this moment on, the baby starts to establish a communicational bond with his mother. He starts developing a desire to listen, to maintain the bond, to keep receiving emotional nourishment: he is yearning to live. The voice of his mother, music and rhythm contain all the linguistic structures on which the baby’s language will be built.

The baby listens to his mother’s voice in a distinctive way, with great prevalence of higher frequencies. Tomatis and his colleagues managed to establish very precisely how the fetus listens. The vibration of the voice descends through the spine and makes the hipbones resound like the case of a violoncello. The fetus, who is completely immersed in amniotic fluid, receives the sound directly in his internal ear. Later, when the baby grows and wants to hear the voice of his mother more clearly, he will try to get his head closer to his mother’s pelvic bones. Tomatis claims that this way, the baby turns and settles in the headfirst position, preparing for birth.