Techniques for indicating to a voice-controlled device that a user is going to provide a voice command to the device. In response to receiving such an indication, the device may prepare to process an audio signal based on sound captured by a microphone of the device for the purpose of identifying the voice command from the audio signal. For instance, a user may utilize a signaling device that includes a button that, when actuated, sends a signal that is received by the voice-controlled device. In response to receiving the signal, a microphone of the voice-controlled device may capture sound that is proximate to the voice-controlled device and may create an audio signal based on the sound. The voice-controlled device may then analyze the audio signal for a voice command of the user or may provide the audio signal to a remote service for identifying the command.