The user explicitly confirms an input with an additional utterance
(``OK''), after examining a candidate input buffered by the interface.
Ideally, confirmation makes use of a sub-state of the decoder that
guarantees very high accuracy for the confirm/disconfirm utterance.
A less-desirable but more reliable alternative is to use a positive
action in some other mode (e.g., a button press) to note confirmation.
Provide an interrupt capability.
This is always true for systems that decode in longer than
real-time.
Applications that typically have a long response latency (should)
provide interruptability. The speech interface should not interfere
with this capability.
