title: how to get mic volume in ios 7?
body: <p>there a view to get mic volume in ios 7?</p>
  
  <pre><code>NSURL *url = [NSURL fileURLWithPath:@"/dev/null"];
  
  NSDictionary *settings = [NSDictionary dictionaryWithObjectsAndKeys:
                            [NSNumber numberWithFloat: 44100.0],                 AVSampleRateKey,
                            [NSNumber numberWithInt: kAudioFormatAppleLossless], AVFormatIDKey,
                            [NSNumber numberWithInt: 0],                         AVNumberOfChannelsKey,
                            [NSNumber numberWithInt: AVAudioQualityMax],         AVEncoderAudioQualityKey,
                            nil];
  
  NSError *error;
  
  recorder = [[AVAudioRecorder alloc] initWithURL:url settings:settings error:&amp;error];
  
  if (recorder) {
      //recorder.delegate = self;
      [recorder prepareToRecord];
      recorder.meteringEnabled = TRUE;
      [recorder record];
      levelTimer = [NSTimer scheduledTimerWithTimeInterval: 0.1 target: self selector: @selector(levelTimerCallback:) userInfo: nil repeats: YES];
  } else {
      NSLog(@"");// mic error message
  }
  
  - (void)levelTimerCallback:(NSTimer *)timer {
      [recorder updateMeters];
  
      const double ALPHA = 0.05;
      double peakPowerForChannel = pow(10, (ALPHA * [recorder averagePowerForChannel:0]));
      db = 20* log10(peakPowerForChannel);
      db += taraturaDb;
      db = db &lt; 0 ? 0 : db;
      lowPassResults = ALPHA * peakPowerForChannel + (1.0 - ALPHA) * lowPassResults;
  
      if (lowPassResults &lt; 0.95) {
          NSLog(@"%f",db);
  }
  </code></pre>
  
  <p>this that worked in iOS6 doesn't work in iOS 7</p>
  
  <p>thanks</p>