It deduction under section 80dd

Some time back, a query was raised by me which would have skipped the attention of our learned viewers and therefore again i am putting it for them to throw their views on this. To get a certificate under section 80 DD for hearing impairment, certificate from CMO is necessary? and what extent the IT benefit will be? Whether 50,000/- or Rs. 1,00,000/-. Further, is it required to produce the vouchers or self certifcation is enough. Kindly throw light on this. o get a certificate under section 80 DD for hearing impairment, certificate from CMO is necessary? and what extent the IT benefit will be? Whether 50,000/- or Rs. 1,00,000/-. Further, is it required to produce the vouchers or self certifcation is enough. Kindly throw light on this. o get a certificate under section 80 DD for hearing impairment, certificate from CMO is necessary? and what extent the IT benefit will be? Whether 50,000/- or Rs. 1,00,000/-. Further, is it required to produce the vouchers or self certifcation is enough. Kindly throw light on this.