The X11 protocol only serves the windows. If we are to forward sound, a [sound server](https://en.wikipedia.org/wiki/Sound_server) is needed. Some related issues: - [X11 forwarding, how to force audio to the host?](https://unix.stackexchange.com/questions/649950/x11-forwarding-how-to-force-audio-to-the-host) - [Should I be able to hear audio using X11 forwarding?](https://superuser.com/questions/61703/should-i-be-able-to-hear-audio-using-x11-forwarding) - [Sound over SSH Connection in MobaXTerm](https://unix.stackexchange.com/questions/355087/sound-over-ssh-connection-in-mobaxterm) [PulseAudio](https://www.freedesktop.org/wiki/Software/PulseAudio/) is one such sound server.
The X11 protocol only serves the windows. If we are to forward sound, a sound server is needed.
Some related issues:
PulseAudio is one such sound server.