The recording was Aqua by Froese, and the liner notes said
"Recorded from nov. '73 to march '74 in Berlin.Special sounds with the artificial head system by Günther Brunschen.
To appreciate fully the revolutionary artificial head system developed by Günther Brunschen listen to side 2 on stereo headphones
demo record for the curious
here is something for the Germanophone
Subject: RE: Spatial Effects
Date: Tue, 9 Jun 2015 08:01:11 +0000
OK for those still reading, it is a system dating from the 60s at least that tries to get a sense of space into recordings using extra information encoded in there. There are the "artificial head": systems used on records like (IIRC) Tangerine Dream or Popol Vuh - I can't find it. These were abandoned because you needed to use headphones to get it properly.