Methods, systems, and apparatus, including computer programs stored on computer storage devices, for multi-tiered command processing are disclosed. One of the methods includes operating an audio processing system to detect voice commands in a set of first commands controlling behavior of the robot and in a set of second commands controlling behavior of the robot, wherein the system detects commands in the set of first commands using a local recognition model that does not require communication over a network, and detects commands in the set of second commands with a server over a network; executing one or more applications to respond to commands in a set of application commands that include commands different from the first commands and second commands; and detecting and carrying out commands, according to a predetermined hierarchy that prioritizes detection of the first commands first, the second commands second, and the application commands third.