Kitten does not hear well

Hello, we just took in my Granddaughters 7 month old kitten Charlie, I think he may either be deaf , or hard of hearing. He does not respond to his name, although I have another cat zazzy who I speak to often. Charlie is fairly new to the family and I still try to let zazzy know he is my baby boy, and is not being replaced, so maybe I don't say Charlies  name enough, but he does not respond to loud noises like zazzy or come when called? How do I find out if he can hear me without expensive exams.

When I talked to my vet about my concerns that Jake had gone totally deaf, she said she had an easy test to find out.  She brought out a small coffee can filled with coins.  Then she closed the curtain in the exam room where I had Jake so he couldn't see her and she dropped it on the floor.  It made me jump   but Jake didn't react a bit so she concluded that he was indeed deaf.  

You could stand behind him and crumple a piece of paper, or jingle keys or maybe have a vacuum cleaner out and when he's not looking, turn it on to see if he reacts.

I remember when we first thought Flowerbelle was deaf. The vet clapped his hands behind her head and she reacted. He concluded she wasn't. Yet she never responded to her name, ignored the vacuum cleaner, etc. She can hear certain frequencies we've discovered. She must have FELT him clapping his hands. :lol3: So yeah - make a big noise from a distance and see what happens. I think that's the best test.