pronounciations do not play in silent mode w/o AirPods connected

Hello,

First of all, thanks for the great app, i'll donate via github, it's a great piece of software.

One complaint: these days many people keep their phones in silent mode, and so far most language-learning apps I've tested are able to circumvent silent mode for pronunciations. With Ringotan however this works with Airpods, but without Airpods I have to disable silent mode in order to hear sounds, which is a tiny, but still a hurdle, especially annoying when I forget to switch silent mode back on, as Ringotan is pretty much the only app that requires disabling it. Please consider a fix, hope it's an easy one and thanks once more!