9. A non-transitory computer storage medium encoded with a computer program, the program comprising instructions that when executed by data processing apparatus cause the data processing apparatus to perform operations comprising: identifying, by a mobile computing device, an identity of a person that is speaking into the mobile computing device; selecting stored biometric information associated with the identified person; determining, by the mobile computing device, that the identified person has stopped speaking into the mobile computing device based at least on the selected biometric information associated with the identified person; and generating a transcription of the person's speech into the mobile device in response to determining that, based at least on the selected biometric information associated with the identified person, the identified person has stopped speaking into the mobile computing device.
13. The computer storage medium of claim 9 , wherein determining that the identified person has stopped speaking into the mobile computing device is based further on information that is specific to the identified person.