Umm ... it may sound weird initially ... but plz do remove wiper cowl & check that area for any cracks or broken/loose wiper arms.
Once happened with me in jdm alto 09, there was a very strange noise from the front, initially felt like a noise from suspension, after alot of khuwari, got to know that it was broken wiper arm hanging inside that area below the wiper cowl & hitting the body upon bumps.