Things change on Glaciations, the five-track album from the duo Kalte. They just change, well, glacially. On the opening cut, “Obliquity,” thin wisps of sound give way to rumbling machinery and ghost echoes (MP3). And on “Luminosity Function,” metallic reverberations are slowly swallowed up by a mix of bird song and semi-melodic effluence (MP3). Such is the manner in which Kalte (aka Deane Hughes and Rik MacLean) itself functions, drawing on field recordings — a common thread for releases on the responsible label, Dark Winter — and bending them, often subsuming them, to their will. The result is a murky electronica, whose impact is strong even if — or, more to the point, because — the sounds themselves are mysteriously muffled.