When listening to decoded digital speech radio, it is bothersome to have the raw radio traffic playing in my ears over top of the decoded sound. To get around this, I am bridging the output of gqrx to a Pulseaudio null sink which dsd is listening on.

I found this answer on askubuntu.com that shows how to create a Pulseaudio null sink in a single line. I’m sure I could have looked through the Pulseaudio docs, but this was one of the first hits on Google.

We will create a null sink called “gqrx_bridge” to bridge the audio output of gqrx to the OSS emulated recording interface at /dev/dsp that dsd is listening on.

pactl load-module module-null-sink sink_name=GQRXBRIDGE sink_properties=device.description="gqrx_bridge"

You can now adjust the target and source sinks for gqrx and dsd in the Pulseaudio volume control panel to use the newly created audio bridge. If you leave the decoded audio sink set to our main sound out, you should only hear decoded sound in your speakers.