It is regional. I have always said 'aitch', but I've moved around the country (England, when I lived there) and further north they tend to say 'haitch'. They also use different words sometimes, and pronounce various words differently. My mother believed you shouldn't be able to know where someone came from from the way they speak, ie nobody should have an accent other than received English (posh speak). That's not the way life is nowadays - so some people will continue to say 'haitch' and talk of barm cakes and speak in accents incomprehensible to others who live in other parts of the country. That is life.