$ sudo pacman -S sox
$ mkdir -p ~/.config/systemd/user/
$ vim ~/.config/systemd/user/usb-audio-keep-alive.service
[Unit]
Description=Keep USB Audio Alive Using sox
[Service]
ExecStart=/usr/bin/play -n -c2 synth sin gain -100
[Install]
WantedBy=default.target
$ systemctl --user start usb-audio-keep-alive.service
$ systemctl --user enable usb-audio-keep-alive.service
Credits https://destinmoulton.com/blog/2021/linux-usb-audio-keep-alive-service/