PulseAudio 4.0 comes with better handling of low-latency requests, optimization while mixing (including ARM NEON), and major Bluetooth redesign for easier maintenance and improved reliability. This release of PulseAudio also sets the default resampler to speex-float-1 for lower CPU usage, adds a new module to apply ducking based on stream roles, and fixes JACK Audio Connection Kit issues. Moreover, PulseAudio 4.0 brings zsh and Bash completion for command-line utilities, fixes to the echo canceler infrastructure and improvements for the Apple Mac OS X and Solaris operating systems.