Can you try if specifying an absolute path fixes the problem? My guess is that it's a working directory problem. Change "test.wav" into something like QDir::tempPath() + "/test.wav" in both createAudioRecorder and endRecordAudio

Hi and welcome to devnet, You have an example on how to use QAudioProbe in the detailed documentation of the class. As for measuring the level of a silent user, it's a completely other topic, you'll have to take into account the noise of the environment of the user.

I don't know the current roadmap of QtMultimedia. But a project that you might be interested in is QtAV