With West Bengal Chief Minister Mamata Banerjee taking the initiative, a cochlear implant -- which can cost up to Rs 10 lakh -- was done for free on Wednesday on a seven-year hearing-impaired girl from a poor family at the state-run SSKM Hospital here.The mother of the girl, Swapnanika Barik had approached Banerjee a few days after the declaration of the assembly poll results last month with a prayer for treatment of her daughter who was deaf from birth, official sources said.The girl, a resident of Basulia village of East Midnapore district's Mahishadal, needed a cochlear implant."As the separated single mother comes from a very poor family, it was impossible for her to buy such an expensive device. After the woman met the Chief Minister at her residence in Kalighat of south Kolkata, Banerjee -- who is also the state Health Minister -- instructed the department to take all possible steps for the child's treatment," an official said.The health department decided to sponsor the child, and the implant was successfully done on Wednesday by ENT specialist Arunabha Sengupta at the SSKM Hospital.This is the first instance where the state health department has sponsored a cochlear implant.