Schoolboy Xiao Gao , 11 , drank and showered with dirt and dust dust . He has not spoken since the prank which went wrong three days ago . Doctors ca n't suffer sudden voice loss and think it might be psychological .
Schoolboy Xiao Gao , 11 , drank water spiked with perfume and chalk dust . He has not spoken since the prank which went wrong five days ago . Doctors ca n't explain sudden voice loss and think it may be psychological .