PURPOSE: To enable handicapped persons having troubles in their ears and mouths to confirm the start of communication with each other, by displaying the state of a telephone circuit before the operation of an information terminal device.

CONSTITUTION: An information terminal device is provided with an MODEM5 connected to a telephone circuit 1, a signal processing circuit 6, a character display part 8 and a keyboard 7. A state display circuit 4 is connected to the information terminal device. The circuit 4 supplies the signal of the circuit 1 to an OR gate 12 via a pulse delaying/modulating circuit 10 and at the same time the output signal of the circuit 6 to the gate 12. Then the synthetic video signal delivered to the output of the circuit 12 is applied to a CRT9 of the part 8. As a result, the state of the circuit 1 can be displayed to the CRT9.