1. In a method for determining an empirically derived acoustic confusability measure, a corpus processing method to generate a recognized corpus, said corpus processing method comprising the steps of: receiving as input a corpus, comprising a set of utterances with corresponding reliable transcriptions; recognizing any utterance among the set of utterances to yield a recognized utterance, wherein said recognized utterance includes at least one decoded frame sequence; coalescing identical sequential phonemes of said at least one decoded frame sequence to yield at least one decoded phoneme sequence; generating, for each corresponding reliable transcription, at least one pronunciation, wherein said at least one pronunciation includes at least one true phoneme sequence; and generating as output a recognized corpus comprising for each said recognized utterance at least said at least one decoded phoneme sequence and said at least one true phoneme sequence.