Today's IVR and transaction-processing applications allow self-service access to automated bank, portfolio, and account information, airline schedules, and movie times. Callers may also place orders, track order status, or use a directory to contact a department or individual. Automated speech recognition enhances the flexibility and power of these IVR applications.

The functionalities that can be delivered by today's IVR speech solutions vary widely and range from recognition of spoken letters and numbers to more complex phrases and sentences. Some applications simply replace touch-tone interfaces with speech-enabled applications that recognize a very limited set of spoken letters and numbers that primarily represent the touch keypad. More advanced applications employ directed dialogue or system prompts that guide users to respond with fairly simple spoken words that can be accurately recognized. Today's most advanced natural language applications enable recognition of more complex phrases and sentences spoken in a conversational manner at a natural speed.

Simple touch-tone replacement is faster and less expensive to develop than directed dialogue or natural language recognition applications. However, touch-tone replacement is also much less sophisticated and does not capture the navigational flexibility and increased call automation potential promised by speech recognition technologies (see Figure 1).

Figure 1. Speech Recognition Spectrum

The following system prompts and caller responses illustrate the different speech-recognition capabilities in these types of applications.

• touch-tone replacement— System Prompt: "For checking information, press or say one." Caller Response: "One."
• directed dialogue— System Prompt: "Would you like checking account information or rate information?" Caller Response: "Checking", or "checking account," or "rates."
• natural language— System Prompt: "What transaction would you like to perform?" Caller Response: "Transfer $500 from checking to savings."