Are Somali cats vocal

No not really

It depends on the cat. My Abyssinian male of 9 is vocal whenever he is playful, hungry, or drawing attention when I've worked too long on the PC and he wants my attention. Sometimes he's vocal when I go to bed, because he just rested and wants to be with me, while I am retiring to the bedroom, although after 5 minutes or less he gives up and goes to sleep again. He is however not vocal when he is satisfied or at ease, unlike some other breeds that are. I'd say the average Abyssinian is probably moderatly vocal, mostly when she/he has needs which aren't fulfilled at the moment.