17. A non-transitory computer storage medium storing a computer program, the program comprising instructions that when executed by one or more computers cause the one or more computers to perform operations comprising: obtaining audio data; accessing first context information associated with the audio data, wherein the first context information that indicates (i) a first geographical location, and a first time; accessing second context information associated with one or more previously typed or previously transcribed terms, wherein the second context information indicates (i) a second geographical location and (ii) a second time; determining a similarity score for the first context information and the second context information based on (i) a degree of a similarity of the second geographical location to the first geographical location and (ii) a degree of a similarity of the second time to the first time; adjusting a language model based on the similarity score to adjust a likelihood that the language model indicates the one or more previously typed or previously transcribed terms as a candidate transcription of the audio data; determining a transcription of the audio data using the adjusted language model; and outputting the transcription that was determined using the adjusted language model.
17. A non-transitory computer storage medium storing a computer program, the program comprising instructions that when executed by one or more computers cause the one or more computers to perform operations comprising: obtaining audio data; accessing first context information associated with the audio data, wherein the first context information that indicates (i) a first geographical location, and a first time; accessing second context information associated with one or more previously typed or previously transcribed terms, wherein the second context information indicates (i) a second geographical location and (ii) a second time; determining a similarity score for the first context information and the second context information based on (i) a degree of a similarity of the second geographical location to the first geographical location and (ii) a degree of a similarity of the second time to the first time; adjusting a language model based on the similarity score to adjust a likelihood that the language model indicates the one or more previously typed or previously transcribed terms as a candidate transcription of the audio data; determining a transcription of the audio data using the adjusted language model; and outputting the transcription that was determined using the adjusted language model. 19. The non-transitory computer storage medium of claim 17 , wherein the first time indicates a first time of day when the audio data was recorded and the second time indicates a second time of day when the one or more previously typed or previously transcribed terms were input; and wherein determining the similarity score comprises determining the similarity score based on a similarity of the second time of day to the first time of day.