<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by skylane:
Most likely the crew was playing the ATIS (Automatic Terminal Information Service) over the cockpit loudspeaker. This way they can stay tuned into ATC via the headsets and listen to the ATIS (weather and runway information) over the loudspeaker.</font>
Probably the most likely scenario. Of course, they should be able to her the audio from multiple sources in their headsets.