GEOFF Gregg (HAS April 14), suggests that sat navs should be sound-only as he believes that the visual display is a dangerous distraction.

Sorry, I disagree. As one who has used satellite navigation since the ones that just gave latitude and longitude, a correctly placed screen reduces the distraction.

I’ve learned the hard way that the screen fitted low down on the console, as it is on many cars, is a menace but a small screen on the car’s glare-screen, just out of one’s line of sight, is far less of a distraction than peering at road signs as you pass them.

I’ve tried audio only, when the lead was too short to reach a safe mounting, it doesn’t work. It’s far better to use the voice as the main guide and glance at the screen arrows. It’s too easy to miss a detail of a sound prompt. There’s too much extraneous noise in a car. Incidentally, I’ve tried a sat nav in my pocket and on the passenger seat. It doesn’t work because it must have good satellite reception, it needs either an external antenna or a placing close to the windscreen to get a good view of the sky.

Random body movements also confuse its sense of direction.

Anthony J. Foster, Peterlee