How to setup the linux default sound

reference link

Check sound sinks

$ pactl list short sinks
0       alsa_output.platform-sound.analog-stereo        module-alsa-card.c      s16le 2ch 44100Hz       SUSPENDED
1       alsa_output.platform-3510000.hda.hdmi-stereo    module-alsa-card.c      s16le 2ch 44100Hz       SUSPENDED

Set default

pactl set-default-sink alsa_output.platform-3510000.hda.hdmi-stereo

or edit

$ sudo vi /etc/pulse//default.pa
add the following
set-default-sink output alsa_output.platform-3510000.hda.hdmi-stereo