My SDL audio app silence when start another player app

SDL Development
1

I use SDL auido functions,such as SDL_OpenAudio, SDL_PauseAudio, etc, to play audio pcm data on Windows platform in my app. Normally, the app work finely! But when I start other apps that use audio driver(for example mp3 player), my app will silence except for make my app in top window. How to solve this problem?

2

any suggestion is helpful for me.