Siamese Cat "Voice" Change

I have a 7 yr old Siamese mix who has always been extremely vocal. I have noticed in the past week to 10 days that he has not been meowing as much and when he does his meow is a little deeper with a slight rasp to it. Everything else seems normal for him appetite, pooping & peeing, playing with his dog. Just wondered if it’s something I should be concerned about.

I once had a cat who “lost her voice” for a while. No one could tell me why. She was an older cat, though.

Hyperthyroid? I think a thyroid issue can cause a voice change.