21 month old often ignores me when I call his name

[Kalypso]

I'm a little unsure whether this behaviour is normal or not. DS has just turned 21 months, and he has never been very good at looking up from play (or whatever else he is doing) when DH or I call his name.

For instance, if he is playing with his cars and I say "DS?", usually he'll act as if he hasn't heard me and continue playing as if I'm not there. However, if I were to say something like "DS - where is my nose?", he'll look up straight away and point to my nose. He does seem to be much more responsive if a stranger/less familiar person says his name, however.

He's saying lots of words, is beginning to talk in sentences, is cuddly, has good eye contact and plays with toys appropriately. He does have a few 'tics' which have come and gone, to be replaced by something new (at the moment, he pushes out his lower jaw a lot when over-excited). He can always be distracted out of his tics; they don't seem 'obsessive' and they are barely noticeable some days.

Is this ignoring thing fairly normal? It almost seems that he doesn't 'get' that when I say "DS?", it means that once I have his attention I'm then going to say or do something else. Should he have this understanding by now?

TIA.

Perfectly normal. He sounds perfectly responsive and interested in his world.

A 21 month old engrossed in what they are doing and ignoring you is what they do. What they are doing right now is more important than everything. At 21 months a child lives in the now. They have no concept of time, the past or the future.

Thank you both for your responses and apologies for the late reply. To be honest, I probably do say his name in a particular tone, which usually signifies I want him to stop what he is doing and move on to something else. He could well have worked out it's better to ignore me! If I think about it, he always responds if I ever call his name loudly in a worried way (i.e. when it looks like he might be about to topple down some steps), so perhaps he's mastered the art of selective hearing already...