I think this should work (I haven’t tested it):

make a new file called default (.) pa in the pulseaudio congfig folder (.config/pulse)

this will mute source_name (replace source_name with your source name):

#include this config file
.include /etc/pulse/default.pa
set-source-mute source_name true

run this command to list source names:

pactl list short sources

Most translators aren’t perfect, they generally can not understand context