IVR (Interactive Voice Response) allows a computer to interpret the speech of a human being as input to the system. Similar to a touch tone system that listens to the unique sound of each button press a user makes, the IVR system analyzes the sound of the user speaking and converts the user's speech to a format it can interpret.

Like a traditional touch tone system, the user navigates the computer system by making menu selections or responding to requests for other, more complex input. With Interactive Voice Response systems, instead of pressing a button on the telephone, the user would just say their answer into the receiver, and the computer uses speech recognition to interpret what they have said and applies it to the current menu options.

For example, saying the number "one" would be converted to a "1" and the computer could interpret that as a menu choice, or as part of a numeric entry like a telephone number or pass code, dependent upon what the computer accepts as valid input as part of the programming for that particular menu system.

The most common use for IVR is as a replacement for touch tones, a faster way for the user to communicate whole words for directory searches or survey responses. For example, when leaving voice mail for a colleague, you could speak their name instead of spelling it out letter by letter by pressing buttons on the telephone.

Additionally, IVR can be helpful for the disabled who may have trouble pressing buttons.

Interactive Voice Response systems also attempt to provide a service that seems more personal than touch tone systems, although the speed and accuracy of the voice recognition algorithms may not be perfect.

Automated systems such as IVR are used in high-volume applications, typically customer support for very large businesses that handle thousands of calls a day.