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I am trying to calculate the db value of sound coming from the microphone in Android. I have used Audio Record class to get 16 bit PCM data from the microphone.

      //init a recorder instance
      recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,ECORDER_SAMPLERATE, RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING, bufferSize);                                   

      recorder.startRecording();

    // and then read 16 bit PCM data
      recorder.read(data, 0, bufferSize);

The range of values for this data is from -32768 to 32767 (signed 2^16).

I believe that these are the quantized values.But I would like to find out what the corresponding voltage value is.What is the voltage value range for a microphone in android ? Is it more or less the same for all smartphones?

Eg : Say the microphone output is 0 to +5 V then 32767 corresponds to +5 V DC .

DntFrgtDSemiCln
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  • After searching through the net, I found out that the amplitude values depend on the ADC used in the device and not on the microphone itself. – DntFrgtDSemiCln Apr 10 '13 at 13:19

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