We've started rolling out a new game update for the PC version of Battlefield 4. Among other items, this update addresses the so called "sound loop crash" that caused the game to freeze. You may experience some downtime while this update is rolling out.

Feb 25 PC Game update notes
-Fix for the so called “sound loop crash” issue that caused the game to freeze
-Fix for an issue that sometimes prevented players from shooting while in the gunner position of a vehicle
-Fix for the headshot icon appearing incorrectly at non-headshot deaths, such as suicide or dying of an explosion
-General stability improvements

Server Patch
R27 Server Update
-Included various server optimizations
-Fix for a server crash that could occur when loading Second Assault maps
-Added a player.onDisconnect RCON event that let’s server owners and anti-cheat notify players why they were disconnected from a server