title: How to test sound level rms algorithm
body: <p>My app. is calculating noise level and peak of frequency of input sound.
  I used FFT to get array of shorts[] buffer , and this is the code : 
  bufferSize = 1024, sampleRate = 44100</p>
  
  <pre><code> int bufferSize = AudioRecord.getMinBufferSize(sapleRate,
                  channelConfiguration, audioEncoding);
          AudioRecord audioRecord = new AudioRecord(
                  MediaRecorder.AudioSource.DEFAULT, sapleRate,
                  channelConfiguration, audioEncoding, bufferSize);
  </code></pre>
  
  <p>and this is converting code :</p>
  
  <pre><code>short[] buffer = new short[blockSize];
          try {
              audioRecord.startRecording();
          } catch (IllegalStateException e) {
              Log.e("Recording failed", e.toString());
          }
          while (started) {
              int bufferReadResult = audioRecord.read(buffer, 0, blockSize);
  
              /*
               * Noise level meter begins here
               */
              // Compute the RMS value. (Note that this does not remove DC).
              double rms = 0;
              for (int i = 0; i &lt; buffer.length; i++) {
                  rms += buffer[i] * buffer[i];
              }
              rms = Math.sqrt(rms / buffer.length);
              mAlpha = 0.9;   mGain = 0.0044;
              /*Compute a smoothed version for less flickering of the
              // display.*/
              mRmsSmoothed = mRmsSmoothed * mAlpha + (1 - mAlpha) * rms;
              double rmsdB = 20.0 * Math.log10(mGain * mRmsSmoothed);
  </code></pre>
  
  <p>Now I want to know if this algorithm works correctly or i'm missing something ?
  And I want to know if it was correct and i have sound in dB displayed on mobile , how to test it ?
  I need any help please , Thanks in advance :)</p>