Is this really a Raven?

I heard a call I had never heard before whilst out walking near Grafham Water in Cambridgeshire on Friday. It was coming from a tall thick hedge bordering a bridle way, so I used the BirdNET app and it identified it as a Raven, although it would seem to be unusual around here. I wish I had recorded a longer clip, but I've (hopefully) attached what I have along with a screenshot of the ID page showing the location. I crept along the hedge carefully, camera at the ready, but tit flew off and all I managed to see through the dense hedge was a large black bird flying across the field on the other side. I hope the audio clip works, if not perhaps someone can let me know how I can upload it