14. A method according to claim 13 comprising when the users input modality is speech, selecting the foreground state of the speech interface, and when the users input modality is non-speech, selecting a background mode of the speech interface.
15. A method according to claim 14 wherein in the foreground state of the speech interface, implementing audio prompts comprising one of speech prompts, earcons, and earcons and speech prompts, and implementing full speech based error recovery, and, in the background state of the speech interface, implementing audio prompts comprising earcons replacing speech prompts, and implementing no speech based error recovery.