Each airplane usually has a ships headset that is always in the airplane. They are usually the cheapest of the cheap but they get the job done if you forget your headset.

I use the QT halos as well. Super comfortable, great audio quality, no bad hair days, and they make the CRJ whisper quiet. I have never heard anyone (including two feds) ask if they are TSO'ed. I am waiting for the UFlyMic QC25 to come out. Once it does I will probably switch to that.