Is my cat deaf? (morelettersforstupidquestionrule)?

Here's why we suspect she's deaf at least in one ear:

1) She never responds to auditory stimuli. she's the only cat among our 4 cats who still doesn't respond to her name. When it's meal time all the cats wake up and come running at the first sound of a bag/can opening but she just stays there sleeping ever so soundly. even when we approach her and call her loudly she doesn't flinch. We literally have to nudge her to wake her up.

2. She's naturally very vocal, but meows relatively louder than the others. I mean her meows are inappropriately loud and random sometimes!

3. She's a white Turkish Angora with heterochromia, which I hear are particularly prone to deafness.

On the other hand, she's just aloof in nature, really. She's completely oblivious to most stimuli around her anyway, she ignores the other cats when they glomp or play with her and she's only set on interacting with us (humans). On the rare occasion that she does get playful with other cats, though, she has perfectly quick reflexes and good coordination.

So, how do we tell for sure if she's deaf or just "autistic" in nature?