He would 'listen' to the Traveler and could understand pieces of what it said. He could never talk to it and the traveler could never directly speak to him. The speakers mask (which now resides in zavala's office) could listen to the travelers thoughts. There were speakers before him that would tell of prophecies good or bad that would sometimes come true or not. The city stopped listening to the speaker of what he had to say since it would usually not come true or meant nothing. The speaker did however hear of the coming red war from the traveler and did nothing of it. I think this 95% accurate, but if you have any questions look in destinypedia.com