I am trying to capture user audio recording using MediaRecorder object.

I did the following

navigator.mediaDevices.getUserMedia({
    audio: {
        channelCount: 1,
        sampleSize: 16
    }, video: false
}).then(stream => {

    var track = stream.getAudioTracks()[0];

    track.applyConstraints({
        channelCount: 1,
        sampleSize: 16
    });

    // Tired to use getSupportedConstraints(), but sampleRate is undefined
    console.log(navigator.mediaDevices.getSupportedConstraints().sampleRate);
});

From researching, it seems that I can’t set the sampleRate for the recorder as the client may not support it. So how can I get the current sampleRate that the recording was captured with?