94 Mercury Cougarhelp please

i have a 94 Mercury Cougar XR7, its an auto transmission and its been slipping for the past couple of months. now the the car is making a banging sound only after 1500 RPM though. could it be the transmission going? i am going to bring it to the mechanic tomorrow to see what is wrong with it for sure ... but if u guys can give me suggestions of what could be rong with it. thanks for the help.

doesnt really sound like the tranny if its only at 1500, u may just have a miss.