I read that Webkit is not fully implemented. For now audio recording is working on Gear 2 with or without camera using CameraApi :

1 – get  a stream navigator.getUserMedia({video: false,audio:true}, cb,cb);

2 – get a CameraControl navigator.tizCamera.createCameraControl(
        stream,
        onAudioControlCreated,
        onAudioControlError
    );

function onAudioControlCreated(control) {
    audioControl = control;
}

3 – apply settings with fileName and recordingFormat

audioControl.recorder.applySettings(settings,cb,cb);

4 – record 

audioControl.recorder.start();

This will generate a sound file

So now my question to tizen developpers : is it possible to use an AudioContext after navigator.getUserMedia({video: false,audio:true}, cb,cb);

var audioContext = new AudioContext();
inputStreamNode = audioContext.createMediaStreamSource(stream);
…
lastNode.connect( audioContext.destination );

https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html

for example to display sound as a waveform on the wearable

Thanks for anwsers