Hi Nick thanks for taking the time to reply. I had tried setting the volume on the Navigon unit to maximum as described in the manual and also used the "radio" volume" control to turn up incoming voice to maximum but to no avail. Co-incidentally I am having problems getting the trip data to start up and for the voice to start up in sat nav. The dealer has suggested replacing the cradle. Strangely the latter problems can be "kick started" by switching the radio on/of button on and then off!!!I suspect a more complex problem.