First, I am an adult with diagnosed ADHD. I take an anti-depressant that works wonders for my ADHD.
I have a white noise machine in several rooms of our house. I use it every day when sleeping. It eliminates or reduces ambient noises that are distracting and disturbing to me. I use it when I need to focus on something important like writing or calculating or thinking.
If I had this as a kid, I believe that I would have excelled in school and in life. It has been a life changer for me. I also tap into a white noise site on the internet. Taking a test with a white noise background would help me concentrate and organize my thoughts.
I take my white noise machine on trips, I would find it more than difficult to live without it.
Hope this is helpful to those reading this.