12. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, if executed by the one or more computers, cause the one or more computers to perform operations comprising: receiving, by a client device, speech data; initiating, by the client device, a local voice dialing operation using the speech data, wherein initiating the local voice dialing operation comprises: extracting, by a feature extraction module on the client device, one or more features from the speech data, and performing, by a speech recognition module on the client device, a speech recognition operation on the extracted features using one or more locally stored speech recognition models; determining, by the client device, that the local voice dialing operation was unsuccessful; in response to determining that the local voice dialing operation was unsuccessful, transmitting, by the client device and to a remote speech processing system, a request to perform a remote voice dialing operation, wherein the request includes the speech data or the extracted features; and receiving, by the client device and from the remote speech processing system, a response to the request.
12. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, if executed by the one or more computers, cause the one or more computers to perform operations comprising: receiving, by a client device, speech data; initiating, by the client device, a local voice dialing operation using the speech data, wherein initiating the local voice dialing operation comprises: extracting, by a feature extraction module on the client device, one or more features from the speech data, and performing, by a speech recognition module on the client device, a speech recognition operation on the extracted features using one or more locally stored speech recognition models; determining, by the client device, that the local voice dialing operation was unsuccessful; in response to determining that the local voice dialing operation was unsuccessful, transmitting, by the client device and to a remote speech processing system, a request to perform a remote voice dialing operation, wherein the request includes the speech data or the extracted features; and receiving, by the client device and from the remote speech processing system, a response to the request. 19. The system of claim 12 , wherein the operations comprise determining, by the client device, whether the response from the remote speech processing system includes a contact telephone number.