Reverb only in headphones

I recorded my podcast last night. Through computer speakers, it sounds fine. Through headphones it sounds like we are in a lecture hall, like that echo. I’m just wondering if anyone knows why?

Possibly an “enhancement” provided by your sound card. You have not said what sort of computer you are on, so I’ve no idea where you would look for that, but if you are on Windows, try looking in the control panel For Windows 7 and earlier, try also looking near the clock/date on the desktop.