All of a sudden I have no sound in the Mirriam-Webster dictionary app. (My phone is NOT in the silent mode) I want to again be able to hear the pronunciation of a word. I have not made any changes that I know of, it just stopped working. When I click on the speaker it LOOKS like it's working but there's no sound. I have an iphone 6 with IOS 11.4.1. I'd appreciate any help. Thanks!