The call of the dormouse!

Well I think it was a dormouse... I am not sure so will check with a friend, a dormouse expert . The thing is... we went down to the in-law's summer house at Lake Balaton this weekend. Whilst sitting in the garden at dusk (where there is Golden Oriole, Spotted Flycatcher, Black Redstart, Nuthatch...) with one of the kids indulging in his pyro-mania at the Bar-B-Q and the other wolfing down the sausages... an errie, whistling call, drifted over in the smoke, from the neighbour's garden. I did not know what it was, and asked, and my mother-in-law (God bless her) promptly piped up "that's a dormouse" (in Hungarian of course). I asked how she knew, as she is not a top-flight naturalist, and she told me that another neighbour's attic had "once been full of them, before a beech marten arrived" and they had all heard those calls many times. For Edible Dormourse the mammal book I have (Collins Field Guide) only says "Vocal: noisy grunts and squeaks". For Common Dormouse it says "Vocalisations include mewing and purring sounds". I will get to the bottom of it...