Ah, now I get it. When they spoke to ATC the 10 units of N1 vibration caused their voices to be distorted. This was obviously picked up by the ATCO who suggested a birdstrike as a plausible reason. Only then was everything clear to the crew.....
Just in case any ATCOs are reading this, I'm not making fun of you - I'm just taking the mickey out of the Times of India.
