How do I change the sound effects on my Droid Turbo 2? I

[AC Question]

I just upgraded to the from Galaxy S5. I am NOT happy with this one. I am hard of hearing and today on a phone call, I couldn't hear. I can't have that, and I understand there are a lot of people with this low volume problem. Under Settings, Apps, I have not found "sound effects". What do I do? Please, help!