1. A method performed by a computer comprising storage and a processor, the method comprising: modeling acoustic data, a phoneme sequence, a grapheme sequence and an alignment between the phoneme sequence and the grapheme sequence to provide a graphoneme model stored in the storage; and retraining, by the processor, a grapheme to phoneme model usable in speech recognition by optimizing the graphoneme model using acoustic data stored in the storage.
8. The method of claim 1 further comprising, collecting a grapheme label for an acoustic waveform received as speech input from a speaker, including by recording the acoustic data, recognizing the acoustic data as a potential grapheme label, obtaining confirmation from the speaker that the potential grapheme label correctly applies to the speech input, and persisting the acoustic data in association with an actual grapheme label that corresponds to the potential grapheme label upon the confirmation.