A voice controlled assistant has a housing to hold one or more microphones, one or more speakers, and various computing components. The housing has an elongated cylindrical body extending along a center axis between a base end and a top end. The microphone(s) are mounted in the top end and the speaker(s) are mounted proximal to the base end. A control knob is rotatably mounted to the top end of the housing to rotate about the center axis. A light indicator is arranged on the control knob to exhibit various appearance states to provide visual feedback with respect to the one or more functions being performed by the assistant. In one case, the light indicator is used to uniquely identify participants involved in a call.