My wife feels invisible

What do I do to make her feel visible? I went upstairs to plug in my cell phone. I looked at my phone and was distracted by an news article. I was up there for at least 15 minutes.  I didn't ask her what she was doing before I went upstairs, and she was trying to solve a problem with her website. Both kids were running amuck (one kept asking for ice cream even though it was just before dinner, and the other fixed a bowl of cereal without asking, again, before dinner). She was yelling out to me to come help but I did not hear her downstairs. She had to abandon what she was doing and it made her feel like what she is doing isn't considered.

I don't want her to feel invisible. Buy saying sorry doesn't fix this. Promising to try harder doesn't fix this. And it isn't making it go away. I don't know what to do.