An automatic injection device includes an injection syringe for injecting liquid provided with a syringe body carrying an injection needle and a piston rod mounted to be able to move inside this syringe body to cover an injection stroke during which the liquid is injected, an external casing and a positioning control member that are telescopic, the relative movement of which controls the operation of the automatic injection device, and control members arranged to selectively control the movement of the syringe body and the movement of the piston inside the positioning control member in order to automatically inject the liquid present in the injection syringe, the automatic injection device further comprising a device for generating sound signals activated during the automatic injection of the liquid present in the injection syringe so as to generate a series of sound signals from the start to the end of the injection.
