A method and apparatus for generating appropriate confirmatory prompts in a speech-enabled, interactive computer system. The method can be incorporated in an interactive voice response system that includes receiving an input audio stream over a voice channel from a users, performing keyword recognition on received input audio as subsequent input audio is being received, and prompting the user with an acknowledgement of the keyword or keywords as subsequent input audio is being received. In another aspect of the method, the volume of the speech input can be continuously monitored. In a further aspect of the method, recognition results and associated confidence values can be combined to select different confirmatory prompts, and the volume is tailored to be the same as, louder than or quieter than the volume of the speech input, so that different types of confirmation can be automatically generated to produce a natural speech-enabled interface.