How To Include External Microphone Audio In Headphones? I have a pair of headphones with an AntLion ModMic (https://antlionaudio.com) that I use for making VoIP calls with a soft phone. Everything is working properly with one small caveat -- I can't hear audio from the microphone in my headphones.

Audio input is coming from the AntLion through a Plantronics USB adapter. Audio output is coming from a USB DAC to my Sony headphones. So separate inputs and outputs.

When I use a single USB headset, the microphone audio is blended in with what I hear in the headphones and I'd like to do the same thing with the two separate sources.

The only solution I have found is to use SoundSource (http://www.rogueamoeba.com/soundsource/) and use the audio play through feature. Not the end of the world, but I was wondering if anyone had any other suggestions.

Thanks in advance!
I'm going to end up sounding like a one-man advertising campaign for Rogue Amoeba ;-)
No affiliation, merely a satisfied user, for many years

Unless you want to mess with the highly unreliable Soundflower - originally made by Cycling 74, once maintained by Rogue Amoeba but now open-sourced at GitHub - then the only way to go is something made &amp; still supported by Rogue Amoeba.  

Audio Hijack, LoopBack &amp; SoundSource are all based on the same [reliable] technology, but tweaked for different sets of user requirements.
SoundSource is the latest - &amp; cheapest - of their offerings.

If it does all that you need, then it's the one to go for.