Do most kids with SPD tone people out or is it just my son?

My son has ADD. The effects of Attention Defect Disorder can be handled with behavior modification techniques that parents and children alike, can benefit from in order to deal with their child's disorder.

In my child's case, he responded to touch as it was a non invasive way to interrupt and break his attention to deal with the matter at hand. So, whenever he was involved with something and I needed his attention, I simply went over to him and put my palm on his shoulder. This helped tremendously when I needed to talk to him and it worked wonders to get him to cooperate with the matter at hand.

Also, I found transitioning from one activity to the next was difficult for my child. So, I put a large clock on the wall and told him in five minute intervals when play time was over and dinner time began. For instance; at 5:45, I told him to look at the clock because when the big hand reaches 12 it will be dinner time. At 5:50, I reminded him to look at the clock. At 5:55 I reminded him it would be five minutes until dinner time. So, when it was dinner time, he expected it and was ready (psychologically and physically).

Your son is not intentionally toning you out, he is having difficulty breaking his concentration/attention to switch activities or to converse with you. Use your touch to break his concentration and you will see that this is an effective way to get his cooperation. Kids like ours need cues to transition themselves, to even the slightest of changes sometimes.

kids just get caught up watching cartoons and don't hear you talking to them

Sometimes Kids get caught up in something they are doing and block out the world. They listen to a TV so good that they block out the world and dive into the TV show. Yes I believe it's normal. A lot of times little kids do that because they are so into something. But before speaking to him get his attention by turning off the TV or whatever is making him distracted.

That's very normal for ADHD.

Remove the object of his intense focus before speaking to him.

no idea what SPD is, but I have ADHD and yes it's perfectly normal for someone with ADHD. Kids with ADHD are not the same as other kids, we are far more intensely focused on things we enjoy. Look up the term hyper focus