Alphabetic filtering of the speech recognition of words uses a key press
to indicate a desired character in an alphabetic filter string, where
each key press represents two or more letters. The key presses can be
disambiguated by recognizing a key-disambiguation utterance in
association with a given key press. A user can select a desired
recognition candidate from a choice list produced by such filtered word
recognition. Ambiguous alphabetic filtering can be performed iteratively
in response to the addition of successive ambiguous key presses. A user
can select to re-recognize the utterance using filtering based on
ambiguous key input after seeing the results of recognition without such
filtering. Unambiguous alphabetic filtering can be performed by using
multiple presses of an ambiguous key to disambiguate which letter is
intended. A user can select between entering text by either large
vocabulary speech recognition or by spelling text by pressing phone keys.