If you are feeling that you can’t hear the same as you used to you, you should have a hearing screening done. This is a procedure also done in young children to make sure that they can still hear at a reasonable level. Read here to learn about what happens during these screenings, and what you might need to do if you have poor results.
You will put on a large headset and hear a series of beeps at different frequencies and volumes. This will help the audiologist figure out where your hearing is failing if it is. It might just be earwax that is blocking sound. For this, you can go to a pediatric doctor or your primary care physician.
Then an audiograph will be produced that measures your results against the expected results for a person in your demographic. Sometimes you will be re-tested if you are far below the threshold. If you have the same results, you might be directed to get a hearing aid.
Keep these things in mind when considering a hearing test for you or your family. This video has some more detailed information about the hearing test and all its technical components.