[CQ-Contest] KDKA 1920 first transmission

[fabio.grisafi at libero.it]

Hi fellow contesters. Excuse me for the topic not related to contesting but... I need your help.
I am studying for an exam I will attend on Sept 5th about Mass Media history. I have listened to a recording of the first ever public radio licensed station, KDKA Pennsylvania. It was Nov 2nd 1920. 
In the audio recording (made with vynil or wire recorder I think) it is heard some CW from an Ham radio station.Ham radio operators were the majority of the radio listeners in that age. It is clear a 5NN in the reception.
Could you ear the callsign?
http://www.audiomicro.com/tracks/dialog/674568

First public transmition here in Italy was October 6th, but on 1924. It was the URI that transmitted the first announcment. We can ear some CW in that recording too.
http://www.youtube.com/watch?v=ArbnavDdxTk
I will be very pleased to receive a feedback.
Regards,
Fabio, IT9GSF (IG9A, II9T, IU9T and... II9P).