Abstract: A compact interface device for use with a communication apparatus, e.g. a cellular phone is described. The interface device enables a user to make a telephone call through a voice command to any other communication apparatus. The interface device includes an adapter having a controller circuit triggered by a switch, in order to (i) dial a predetermined number associated with a remote service provider, and (ii) terminate the connection; a speaker for reproducing incoming signals of the phone call; and a microphone for receiving audio signals generated by the user. According to another aspect of the invention, there is provided a method of making a telephone call through a voice command by using the interface device.