Y u changed Disc Pads, u should go to a good mechanic, Original Pads when new, they make little sound when applied lightly, I f u press it with a little more pressure, it will not make sound. The sound is due to golden grains of copper in it. But get opinion from a good mechanic.
When the pad will be used more than 1000 kms, this sound will be vanished, if discs are normal.