After investigating I figured out that this has a direct connection to the sampling rate (may be obvious but I skip it somehow).
So, setting this will output a solid number every 100 milliseconds:
this.mediaRecorder.setAudioSamplingRate(8000);
this every 40 milliseconds:
this.mediaRecorder.setAudioSamplingRate(16000);
and this every 10 milliseconds:
this.mediaRecorder.setAudioSamplingRate(44100);
Just remember that you can use 44100 as a sampling rate for AAC audio encoder and 16000 for AMR_WB. The AMR_NB only supports 8000 as the sampling rate.