12. The method of claim 10 , further comprising: in response to failing to authenticate that the speech input is spoken by an authorized user of the device, outputting an error indication.
10. A method comprising: while a device is in a locked state: receiving a speech input at the device, the speech input including a command associated with a restricted feature of the device; authenticating, using the speech input, whether the speech input is spoken by an authorized user of the device, wherein the authenticating includes comparing the speech input to a previously generated voiceprint; in response to authenticating that the speech input is spoken by an authorized user of the device, executing the command identified in the speech input to invoke the restricted feature of the device; and in response to not authenticating that the speech input is spoken by an authorized user of the device, forgo executing the command identified in the speech input to invoke the restricted feature of the device; where the method is performed by one or more processors of the device.