My cat Boots is 16 yo and has recently started to miaow very loudly all the time. He is very vocal every time he comes in and also during the night, he even sits staring at me miaowing for no reason (well I don't know any reason), he is healthy with a good appetite and I am just wondering if perhaps he is going a bit senile, any cat slaves here who has same problem.
Is he going deaf? One of our cats started doing this (usually late at night) when she became a bit hard of hearing -poor dear.
Ever listened to someone talking while they have headphones on? similar reason I expect.
Has he been for a checkup recently? At this age the protein level in their diets normally needs to be reduced to take the strain off their kidneys -which are normally getting a bit hammered by this age.
It does sound like it could be senility, or it could be hyperthyroidism - has his personality changed at all? They can check the thyroid with a blood test and it is treatable. It might be worth a wee trip to the vets.
Suggest trip to vet. I have three loud cats but they are gobby all the time, think they own the place, but if your boy has been a good quiet cat until now then yes, I agree with mustard, he might not be able to hear himself. Or he might be wanting to tell you something, like "I wouldn't mind a trip to the vet" - I'd take him if I were you, any change of habit needs checking over.