8. A computer-implemented method, comprising: receiving an audio input and a facial image sequence for a period of time at an electronic device, the audio input including speech inputs from multiple speakers; extracting a speech input of a particular speaker from the audio input based on the received facial image sequence, including selecting portions of the audio input that correspond to speech movement indicated by the facial image sequence, at least one selected portion including a decipherable segment and an indecipherable segment; and processing the extracted speech input into a symbol sequence, the processing including: converting the decipherable segment into a first sub symbol sequence portion, the converting including: detecting separations between spoken words in the decipherable segment based on the facial image sequence, and processing the decipherable portion into the first sub symbol sequence portion based in part on the detected separations; processing a portion of the facial image sequence that corresponds temporally to the indecipherable segment into a second sub symbol sequence portion; and integrating the first sub symbol sequence portion and the second sub symbol sequence portion in temporal order to form one of the corresponding symbol sequence portions.
16. The computer-implemented method of claim 8 , wherein the indecipherable segment is masked by ambient noise or an audio input portion in which data is missing.