Walking on pavement tiles: socks. Recorded with a zoom h2 in a basement of a house: a wooden container filled with earth onto which three larger paving slabs were placed. Normalized with audacity.
Walking on a wooden floor: bare feet. Recorded with a zoom h2 in a basement of a house: a large wooden table placed on a carpet over concrete. Normalized with audacity.
Walking on soil: sneakers. Recorded with a zoom h2 in a basement of a house: a wooden container placed on a carpet filled with soil. Normalized with audacity.
It is a monotone and low sound because it constantly repeated at certain time, therefore we have need to use a high gain to record it. It is the sound of the barefoot feet walking on the ground.