7. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: receiving, at a computing device, a request including a speech data representation of an utterance or feature data extracted from the speech data representation of the utterance; obtaining, by the computing device, a transcription of the utterance by applying a speech recognition model to the speech data representation of the utterance or the feature data extracted from the speech data representation of the utterance; identifying, by the computing device, a keyword that occurs in the transcription of the utterance; and initiating, by the computing device, a voice dialing operation between communication devices based at least on identifying the keyword.
10. The system of claim 7 , the operations comprising: updating the speech recognition model using the speech data representation of an utterance or feature data extracted from the speech data representation of the utterance.