OK, glad that was helpful. You don’t actually have to modify the framework in order to turn on sound mixing, it is not currently part of the public API and therefore likely to change in future versions but for the time being you can turn on sound mixing simply by including the line you referenced above right before you do startListeningWithLanguageModelAtPath:. It might be necessary for you to import AudioSessionManager.h in the view controller from which you want to do that.