title: What is an optimal setting for AAC voice recording with AVAudioSession?
body: <p>I'm looking to record voice on the iPhone and produce a file that is optimized for small size and recording quality for voice.  With the settings below for AAC I'm getting a small file size, but I'm not sure I'm getting optimal quality.   Other than trial and error, is there anything I can turn to, or any recommendations?</p>
  
  <pre><code>[recordSetting setValue:[NSNumber numberWithFloat:8000.0] forKey:AVSampleRateKey];
  [recordSetting setValue:[NSNumber numberWithInt:kAudioFormatMPEG4AAC] forKey:AVFormatIDKey]; 
  [recordSetting setValue:[NSNumber numberWithInt: 1] forKey:AVNumberOfChannelsKey];
  [recordSetting setObject:[NSNumber numberWithInt:AVAudioQualityLow] forKey: AVEncoderAudioQualityKey]; 
  [recordSetting setValue:[NSNumber numberWithInt: 8000] forKey:AVEncoderBitRateKey];
  </code></pre>