'...everyone (even babies) knows that wooden xylophones make a rubbish noise.'
This sort of very fine xylophone comes from Mozambique. They are called Timbila.
Now, it would be unreasonable to complain of a journalist to whom Greek was, well, all Greek, but really the smallest amount of research would have revealed that if xylophone isn't made of wood then it isn't a xylophone. It's a glockenspiel.
Word To Use Today: xylophone. Or glockenspiel. The first comes from the Greek xulon, which means wood, and phōnē, voice or sound; the second comes from German words meaning bell and play.