Techniques for identifying users that issue audio commands based on signatures associated with the commands and additional characteristics associated with the commands. For instance, a device that includes a microphone may capture audio uttered by a user. The device, or another device, may then compare a signature associated with a generated audio signal to audio signatures associated with known users. For instance, the device may have access to multiple audio signatures, each of which is unique to a respective user that has previously interacted with the device or with another device. The device may then use this comparison to help identify the user that uttered the audio. In addition, however, the device may utilize a characteristic other than the audio signature. Using both the comparison of the audio signature to the previously received signatures along with the additional characteristic(s), the device may make a presumed identification of the user.