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I am trying to record the sound from the MIC and draw a live graph. I am able to record and draw the graph. The problem is the values that are recorded using the code below are not accurate for example ... the image below is what i get when there is no sound at all present. I have seen examples using the fft but I am noot sure if that will be of any help in my case as I am trying to draw a time domain graph and I see no purpose to convert it to frequency domain (for now). Others are using average power, this might be helpful but I am not sure.

Thanks for any help.

enter image description here

bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE,RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING);

    recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,
            RECORDER_SAMPLERATE, RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING, bufferSize);

    short data [] = new short[bufferSize];

    while (!Thread.interrupted()) {

        recorder.startRecording();

        recorder.read(data, 0, bufferSize);

        recorder.stop();

        for (short s : data)
        {
            try {
                Thread.sleep((long) 300.00);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            postUI (Math.abs(s));
        }
    }

    recorder.release();
user591124
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  • hi how did you get amplitude of sound in audiorecorder please help – Aashish Bhatnagar Jul 27 '12 at 07:34
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    recorder = new AudioRecord(MediaRecorder.AudioSource.MIC, RECORDER_SAMPLERATE, RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING, bufferSize); recorder.startRecording(); recorder.read(data, 0, bufferSize); recorder.stop(); for (short s : data) { average += Math.abs(s); } – user591124 Aug 10 '12 at 09:54

1 Answers1

1

Try using a higher sampling rate. The maximum is 48000, but 44100 is standard.

Also, it is possible the microphone is just recording background noise.

gregm
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