Delta 1455 declared a precautionary emergency due to passengers smelling fumes, and is returning to Atlanta. 7/29/2015 app. 10AM
Playing armchair quarterback, PIC could have diverted to Memphis, but ATL is a big hub for Delta. Also, BHM is on the way back, not much more distance than Memphis if situation had gotten worse.
Flight was heading to LAX.
I don’t know of a better way to share the audio, but via my cloud-drive link, which is not embedded, but downloadable.