Hi,

According to PIB, hearing impairment do comes under the PWD act ,1995 according to which a person who has a hearing loss  of minimum 60 dBHL or more in the better ear for normal conversational range.So for your question it's a yes, hearing impairment will get reservation under PWD.All you need to do for reservation is to get a certificate of hearing disability filled .Keep one more thing in mind that this certificate holds lifelong validity when issued to a disabled person above 18 years of age or else this card is to be updated once in every five years.

Hope this helps you