Yup! Mine does and he doesn’t.
If he used to respond or responds to others besides you, he’s probably just ignoring you lol. My daughter does the same thing. She started this around 10 months.
He could also have fluid in his ears. If it keeps up, I’d take him to get his ears checked.
How verbal is he? Can you ask him "what's your name?" and have him respond? Or say something like "mommy loves..." and point to him and wait to respond? If he can do that, can you get the same results in a low volume voice? If so, yeah he's tuned you out. Don't think of it as ignoring you, but just being engrossed in his own beautiful world.
Mine does it when he wants. One thing I read was if they are busy with a task (playing or something else) their brain is focused. It’s like us not wanting to be interrupted. It may not look like something to us, but they are busy.