The only answer I can give is based on my experience. There are a lot of variables to consider that aren't mentioned here. That being said, if you are at all concerned you should talk to your child's doctor.
Of 7 children we have 1 with mild autism and 2 with auditory processing disorder. I am in no way suggesting that your child has either one of these conditions (or any condition for that matter). I am simply illustrating that there are a lot of different possibilities beyond 'Is this normal?'
In the case of the autistic child we thought he had hearing loss, but he didn't. In the case the boy and girl with auditory processing disorder we learned (rather late in their education) that they could hear just fine. Our daughter in particular would (and still does) have delayed responses. Often she stammers or has to start all over with her answers. What distracts them in the room wouldn't distract most of us but for them it does.
Normal ranges don't exist as our children do not live in a vacuum. Each child has different strengths and weaknesses. Some children have learning disabilities but use their strengths to mask them.
You will have to pay close attention to what is happening every time you are talking with you child and their reaction is delayed. Do they look confused, is there noise in the room, is a device on and in their field of vision, are your questions multi-tiered (they have to understand the first part of a question before they can answer all of the question. etc?
Our daughter for years was unable to follow directions if they had more than 2 steps. Broken down and spoon-fed she can complete tasks. We had insisted for years they be tested at school and it wasn't until we moved to a new district that they were tested (and had follow up tests).
Only a present parent that knows their child can tell what is normal. If you have any reservations talk to your doctor and follow up often, as in my experience they don't always listen but our 'gut feeling' that something was wrong has always been correct.
My only regret for my children is that we didn't insist more and get help for them sooner.
