It comes with the age

Her Highness is losing her hearing.

It occurred to me when I was typing with bits_2_whole about one of our mother's cats who is about the same age than HH (actually HH is about six months older) and has apparently lost (most of) her hearing.
I have been wondering for a while why HH is so cranky and doesn't let me go anywhere in the apartment without yelling like someone going to slaughter... apparently the reason is that she doesn't know that I am at home, as she can't hear me, and she gets worried where I got all of the sudden.
Fact is that she is 13 years old (turned about month ago) cat with blue eyes, so, what else could it be? (Taking that her fur is shiny and soft, she eats well for a cat of her age and she's still relatively active.)

How I know she can't hear me? Snap your fingers behind cat's head. If there's no reaction the cat doesn't hear you. I only get a reaction from HH when I snap my fingers right next to her ear.
And she has been much more quiet lately as now when she cries I let her see me. It ends it, always.