12. The system of claim 7 , the computer-readable storage medium having additional instructions stored which, when executed by the processor, cause the processor to perform operations comprising: determining that a plurality of previously stored speech models on the mobile device have likelihood scores below a threshold likelihood score, to yield below threshold speech models; and removing the below threshold speech models from the mobile device.
13. The system of claim 12 , wherein the removing of the below threshold speech models from the mobile device occurs only until a threshold amount of storage space on the mobile device is freed.