My son is moving to live on a farm near Chichester. Most of the locals have general purpose southern accents and are easily understood but some of the old farmers have a totally different accent where I often have had to pretend I didn't hear and say "pardon?" just to but time and work out what they're saying. It's rather like the situation in parts of Wales where most people speak English but the farmers speak Welsh. In many parts of Lancashire you can tell which end of the street someone was born on from their accent.