android: Detect sound level

Question

Using MediaRecorder I capture sound from device's microphone. From the sound I get I need only to analyze the sound volume (sound loudness), without saving the sound to a file.

Two questions:

1. How do I get the loudness for the sound at a given moment in time?
2. How do I do the analyze without saving the sound to a file?

Thank you.

Answer 1

1. Use mRecorder.getMaxAmplitude();

2. For the analysis of sound without saving all you need is use mRecorder.setOutputFile("/dev/null");

Here´s an example, I hope this helps

public class SoundMeter {      private MediaRecorder mRecorder = null;      public void start() {             if (mRecorder == null) {                     mRecorder = new MediaRecorder();                     mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);                     mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);                     mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);                     mRecorder.setOutputFile("/dev/null");                      mRecorder.prepare();                     mRecorder.start();             }     }      public void stop() {             if (mRecorder != null) {                     mRecorder.stop();                            mRecorder.release();                     mRecorder = null;             }     }      public double getAmplitude() {             if (mRecorder != null)                     return  mRecorder.getMaxAmplitude();             else                     return 0;      } }