A navigation apparatus (200) comprises a processing resource (202) arranged to support an operating environment and a route follower (256) supported by the operating environment and arranged to monitor progression, when in use, along a route to be followed. The apparatus also comprises an instruction generator (260) supported by the operating environment and arranged to determine an identity of a location in advance of the location being reached where a manoeuvre has to be executed in order to continue following the route, and to generate manoeuvre data in relation to the manoeuvre. The apparatus further comprises a voice command generator (266) supported by the operating environment and arranged to obtain the manoeuvre data and to generate in response to the manoeuvre data voice instruction data for reproduction by a loudspeaker (276) as an audible voice instruction. The manoeuvre data comprises route manoeuvre instruction component data and supplementary descriptive instruction component data.