Every 20 seconds, a check is made within the world for every player. It checks within a 5 block range of each player for at least 5 Spore Blocks (including vanilla Mycelium). If that threshold is met, creepy audio known as 'strange silence' will begin to play for all applicable players. This audio is designed to make players feel unnerved in infested areas. There are four variations of the track, each lasting 20 seconds, causing it to loop if the player(s) stay within their infested area(s).
Spore Blocks Content