Yes. Onyx has a headphone jack that supports most newer standard 3.5mm headphones or headphones with built-in microphone.
When you plug in your headset, Onyx will still continue to use the mic in the Onyx. Headset mics are not currently supported. Make sure to move your Onyx closer to your mouth so your friends can hear you clearly.
Onyx does not currently support wireless headphones.