pulseaudio-module-x11 1:4.0-0ubuntu9 (amd64 binary) in ubuntu trusty

 PulseAudio, previously known as Polypaudio, is a sound server for POSIX and
 WIN32 systems. It is a drop in replacement for the ESD sound server with
 much better latency, mixing/re-sampling quality and overall architecture.
 .
 This module enables PulseAudio to publish itself as the default sound
 server to the X11 root window automatically upon startup. There is also a
 module to playback a sound file in place of the X11 bell beep.
 .
 The modules are called module-x11-publish and module-x11-bell.