QUOTE(kimmym1 @ Jul 21 2008, 12:39 AM)

has anybody any experience of what actually happens in the aural part, one teacher i had said you had to sing a scale and suggested i took singing lessons, if anybody has any experience of what you are expected to do and would like to pass it on, would be appreciated . kim

Kim, did your teacher tell you why he/she suggested that you should take singing lessons?
Voice quality is not what the examiners are looking for in an aural exam for instrumentalists. You are not required to sing like a voice exam candidate or a soprano. You only have to sing in tune.
I am also an adult learner right now, though I have also taken exams as a child many years back.
My experience is, as long as you sing mostly in tune and demonstrate that you have a good idea where you are going in the melody etc, the examiner considers the section correct. Just this March, I went for my Grade 5 piano exam. I was asked to sing back a melody that was played to me, and also to sight-sing from a 6-note passage. The very first time I opened my mouth, my throat was completely dry from anxiety, and the first note came out broken, sounding like a duck quack. Even I was quite shocked by the poor sound I produced, and was rather embarassed by it. However, I was not penalised on that at all. I am very sure about that because the comment wrote "Except a slip in clapping, everything else was correct."
So you do not have to worry about how well you sing. Instead, it might be worth considering voice lessons if you have problems holding a tune, or are afraid to sing out loud. Those might be confidence issues, which could be alleviated with proper instruction.
No worries at all, aural exams are intimidating and puzzling, but they always turn out pretty fine when you receive your results!
Are you familiar with the aural syllabus?