My big, black, longhaired cat has always been very vocal. Now at the age of 17, he's extremely vocal! When he's not sleeping, he's talking. He has hyperthyroidism, and one of the symptoms of that is being vocal. He wails away in the house & won't pipe down until you find him & calm him down. It might be worth asking your vet to carryout a test for hyperthyroidism, as this is a very common ailment in ageing cats and they need medication to keep it under control.
Private spinal surgeon appointment
Just a little self-indulgent weep
; this continues till he's back on the ground and safely away. 