It is far more likely that we we will start "communicating" with alien intelligence long before we actually "meet" them, simply due to the distance versus speed-of-light constraints. I guess you do know, that the closest star to us (other then our sun) -- Alpha Centauri is about 4.5 light years away, meaning it would take 9 years for light or electromagnetic signals (communication) to do a round-trip, while we currently don't have any technology that would allow us to even reach 1% of that speed with a space-ship, so making a trip is far beyond a human life-time.
If / when we detect any sign of alien life in the form of electromagnetic signals, I'm sure we will make all possible efforts to start communicating via such remote technologies. Also note, that we already use electromagnetic technology for long-range communication even though we are not capable of "hearing" or understanding it directly with our bodily senses, thus we can certainly develop technologies to translate whatever way the aliens communicate, be it color / light patterns, smells or whatever else apart from sound frequencies we use.