37. The system of claim 31 , wherein the instructions further cause the one or more processors to: determine a relevant subset of the shared pronunciation lexicon based on the context of the third user device, wherein the speech-to-text conversion on the audio data is performed using the determined relevant subset of the shared pronunciation lexicon to generate the textual representation of the user speech.
31. A system comprising: one or more processors; memory storing one or more programs, the one or more programs comprising instructions, when executed by the one or more processors, cause the one or more processors to: receive, from a first user device; a first pronunciation for a first named entity; receive, from a second user device, a second pronunciation for the first named entity; store the first and second pronunciations for the first named entity in a shared pronunciation lexicon, receive, from a third user device, audio data representing user speech and a context of the third user device, the user speech including the first named entity in spoken form; and perform speech-to-text conversion on the audio data to generate a textual representation of the user speech, the speech-to-text conversion comprising selecting, for comparison with the audio data, the stored first pronunciation or the stored second pronunciation for the first named entity based on the context.