d from your touch-tone telephone. This enables you to obtain information such as your account balance and the checks that have cleared. You may also instruct the computer to transfer funds from one account to another. Another example of IVR is encountered when you call to request railroad train schedule information. The automated sys- tem, using Interactive Voice Response will prompt you with instructions such as the following: If you're traveling today, press 1; for schedule information tomorrow, press 2; if you're leaving from Grand Central Station, press 1; if you're going to Grand Central Station, press 2; enter the first four letters of the station you're leaving from, using the buttons on your touch-tone tele- phone; enter the time of day you wish to leave, followed by AM or PM." Often you will be instructed to 'Press 1 if this is correct, after the system has repeated your selections back to you. The system will then speak to you, providing the information you have requested. IVR is also widely used in Call Centers in con- junction with an Automatic Call Distributor. Another way to define IVR is by its basic purpose, to use the telephone as an interface with a computer to receive or input data. Although not all IVR applications manipulate data, most receive and disseminate it. The Telecom Handbook 171 INTERACTIVE VOICE RESPONSE Some IVR systems enable the caller to speak responses to the IVR questions, rather than using touch-tone signals. This is possible due to what is called speech recognition. The system might instruct the caller to "press 1 or say 'sales' " (for the sales department). The responses are usually simple one-word phrases. The term IVR sometimes refers to the application, but also refers to the system itself, which is usually PC-or server-based. The system is also sometimes called a VRU (Voice Response Unit), particularly the part that provides the communications between the touch-tone signals and the computer. The most popular PC operating systems for IVR are Windows 2000 and Windows NT. 