An apparatus comprising: a controller configured to: receive one or more sensed signals from one or more wearable sensors, wherein a wearable sensor is for sensing a user's body and outputting a sensed signal dependent upon one or more biological processes of the user; process the one or more sensed signals and detect one or more bio signals that are determined by the one or more biological processes of the user; and process the one or more sensed signals to detect a user input signal indicative of: the user touching the user's body, and/or the user touching at least one of the wearable sensors, and/or relative movement of at least one of the wearable sensors relative to the user's body, and process the user input signal to identify a user input command.