Thinking Too Much

I wonder what sounds I am not hearing, but do not know I am not hearing because I have no one there to tell me of that sound. Also, others may not think twice of a noise so they may not outwardly say it so I wouldn’t know to listen for a noise. I think this may have something to do with my ADHD but sometimes I will not hear something until it is brought to my attention by someone. Then, when I focus on the noise I am able to hear it. Thinking about this I wondering if I am actually hearing it or if it is just a memory of that sound. I think I am thinking too much and need to go to bed…