You just took me all the way back to being 7 or 8! We lived in a very similar location to Billy Casper in the film "Kes". 50 yds from our house you were straight into huge rolling fields that seemed to go on forever and every summer they were filled with skylarks. I would often take off into the fields and be gone all day, sometimes with a few other kids, sometimes solo. It's all gone now, covered with a couple of thousand houses.
It was the sound of my childhood too. Kes is a wonderful film and one of my favourites, i can relate to it very much, escaping from the grime and noise of heavy industry to wandering across the fields hearing the sweet music of skylarks the contrast between the two was remarkable and gave me a love for nature. Another evocative sound is the call of Peewits. ATB