To be worried that DS is behind?

[WomanEmpire]

He's only 9 months. But hear me out:

Physically he's doing great, he crawls, climbs stairs, stands unaided and walks with his baby walker.
He has no teeth yet and no sign of them coming through which I think is a bit odd but not concerned.
He rarely makes a noise except crying. He occasionally shrieks very loudly if excited, and I've heard like a slight hum before but not often. He cries when hungry/tired/etc (he's a bad sleeper during the night) but I've never seen an attempt to babble. I think DS1 had a lot more understanding of words at this point kiss, bye, huge, no, etc but I don't think DS2 does. He doesn't make those 'baby' noises IYSWIM. I'm not 100% convinced he knows his name as he will only look when I say his name half the time I just called him Nigel and he turned round for it and not his actual name
Should I be concerned? We all converse with him a lot, he is read too etc

All sounds completely normal.

Could it be his hearing? It could be nothing, babies develop at different rates but if you are genuinely concerned I would see your health visitor or gp.

The teeth thing is petty normal, two of my three children didn't have teeth until 12 months. My 17 month old still only has 6 teeth.

EB perhaps, this is kindness of what I was thinking. Just sometimes he's sitting playing so nicely alongside his brother and I just find it so odd that no noise is made by him when his DS1 is so noisy vocal!
We have an appointment next week with the GP to check a hernia so will mention it then.

He just looks so funny walking, he's on the 10th percentile, no hair and no teeth

*kind of

My 8 month old does non of that and shes bang on where she should be developmentally so I think youre alright lol