Saving audio input of Android Stock speech recognition engine

I am trying to save in a file the audio data listened by speech recognition service of android.

Actually I implement RecognitionListener as explained here: Speech to Text on Android

save the data into a buffer as illustrated here: Capturing audio sent to Google's speech recognition server

and write the buffer to a Wav file, as in here. Android Record raw bytes into WAVE file for Http Streaming

My problem is how to get appropriate audio settings to save in the wav file's headers. In fact when I play the wav file only hear strange noise, with this parameters,

short nChannels=2;// audio channels
int sRate=44100;    // Sample rate
short bSamples = 16;// byteSample

or nothing with this:

short nChannels=1;// audio channels
int sRate=8000;    // Sample rate
short bSamples = 16;// byteSample

What is confusing is that looking at parameters of the speech recognition task from logcat I find first Set PLAYBACK sample rate to 44100 HZ:

    12-20 14:41:34.007: DEBUG/AudioHardwareALSA(2364): Set PLAYBACK PCM format to S16_LE (Signed 16 bit Little Endian)
    12-20 14:41:34.007: DEBUG/AudioHardwareALSA(2364): Using 2 channels for PLAYBACK.
    12-20 14:41:34.007: DEBUG/AudioHardwareALSA(2364): Set PLAYBACK sample rate to 44100 HZ
    12-20 14:41:34.007: DEBUG/AudioHardwareALSA(2364): Buffer size: 2048
    12-20 14:41:34.007: DEBUG/AudioHardwareALSA(2364): Latency: 46439

and then aInfo.SampleRate = 8000 when it plays the file to send to google server:

    12-20 14:41:36.1