Strange Noises

Everyone must have seen the classic 70s film 'Close Encounters of the Third Kind' which depicted an imagined first contact with an alien civilisation and can hum that 5 note tune right now which is Spielberg's idea of how we would communicate with an alien life force.
Humans have been sending signals and radio waves out into the depths of space since the space programme began but as yet nobody has come over to see who it is making such a racket in the Milky Way but they may have sent a message back as we have received quite a few unexplained noises coming in our general direction that scientists have no explanation for.
One such signal was received in 1977 by the Big Ear radio observatory in Ohio, a 72 second signal which was never heard again and 40 years later can still not be explained by scientists who have ruled out satellites, aircraft, ground-based transmitters on Earth and general space noise.
This week NASA have picked up another unexplained and baffling sound from space, this time they traced it to the Perseus galaxy cluster, 240 million light years away.
What if the source of the 1977 and 2014 sounds were a signals coming from another planet probing the sky and directing signals towards location they themselves thought may contain life.
Two thoughts.
Firstly, if we are only now hearing sounds which were emitted 240 million light years ago, any alien civilisation that had the technology then to do what we are only doing now, would be so far superior to us that the feeble attempts to contact them that we are making would be as incompatible as trying to send a smoke signal to an email account.  
In the opposite direction, we will not have the technology to catch communications sent by a civilisation many millenniums further down the communications evolutionary time line than us.
Secondly, do we really want to announce ourselves to a hugely advanced civilisation that would view us with as much disdain as we view an insect?
It is just a shame that the mysterious sounds are not coming from Uranus, that would just be too much to ask but for now there is no noise coming from Uranus although by all accounts the smell isn't great. Oh grow up.