Communication with a computer using telephones

A telephone system having a telephone network line for connection to an external phone line. The telephone system also includes a computer system and a telephone coupled to the telephone network line, and the telephone is taken off-hook to enter a voice command. A transmitter communicates the voice command from the telephone to the computer system without the telephone seizing the external phone line. A computer interface unit is connected to the computer system to receive the voice transmitted from the telephone and to transmit voice signals transmitted by the computer system to the telephone. A phone interface unit is connected between the telephone and telephone network line, and the phone interface unit is selectable between a first mode and a second mode. The phone interface unit connects the telephone to the telephone network line if it is in the first mode, and isolates the telephone from the telephone network line if it is in the second mode. If an external phone call is detected from the external phone line, the phone interface unit can be selected to be in the first mode if the external call is present. The computer system includes communication software for controlling communication in the telephone system, including receiving a voice command transmitted from the telephone when the telephone is off-hook, and controlling the phone interface unit to isolate the telephone from the external phone line when receiving the voice command from the telephone line.