According to the CRA (http://www.cra-arc.gc.ca/tx/ndvdls/tpcs/ncm-tx/rtrn/cmpltng/ddctns/lns300-350/330-331/dtlxpns-eng.ht...), hearing aids are eligible medical expenses.
This article describes how to enter medical expenses: https://turbotax.community.intuit.ca/questions/1358787-where-do-i-enter-medical-expenses-on-turbo-ta...