The eminent Leslie Valentine Grinsell spoke to a local farmer in Puesdown Inn in 1959. He told him that the older farmers in the area would say that when the plough went over one of these longbarrows, the ground sounded hollow.
The south barrow used to have 2 upright stones at its SE end, but these were gone by the 1920s. Got in the way of the plough probably. Oh well. But they kind of indicate the ‘megalithic’ nature of the barrow and hence that it might well have sounded hollow, maybe having a chamber inside.
(Trans Brist Gloc Arch Soc 1960 – Gloucestershire Barrows)