1. list devices:
$ pactl list sources | grep "Name:"
	Name: alsa_input.usb-MACROSILICON_USB_Video-02.analog-stereo
	Name: alsa_output.pci-0000_00_1b.0.analog-stereo.monitor
	Name: alsa_input.pci-0000_00_1b.0.analog-stereo

2. play device:
$ pw-loopback -C "alsa_input.usb-MACROSILICON_USB_Video-02.analog-stereo"