when mobs walk, they leave their sound behind, so the sound seems to come from the air around the mob.(this may seem more like a feature request than a bug report or may even be intended, or may not be worth the time to fix) reproducing is simple, make the weather rain using the command /weather rain, then use a command block and run the command /summon Enderman , and set it to "repeat" and "always active". then the endermen will teleport around, sometimes leaving "enderman vwoops" (excluding teleporting) behind. if you turn on subtitles, the subtitles prove that they leave their sound behind.