Pulse Audio is an advanced network sound server. To put it simply, Pulse Audio is a background process designed to accept sound input from a source, and redirect it to devices like sound cards, or other processes.
Pulse Audio allows the mixing of multiple audio streams, the sound playback or record on a different machine than the one it is running on, offers a Sound API abstraction, alleviating the need for multiple backends in applications to handle the wide diversity of sound systems, and gives the possibility of doing things like individual volumes per application. Maybe this diagram will help you understand the way things work:
Yesterday, Pulse Audio developers announced the release of version 2.0 which comes with some great new features and additions:
- Alternate sample rates
- Jack detection
- Echo cancellation: WebRTC canceller, automatic gain control, drift compensation
- Virtual Surround module
- Xen Paravirtualised audio sink
- Fixed HURD support
- A2DP decoder quality improvements
If you want to read more details about the new key features visit this webpage.