SimpleAudioRecorder - Microphone Access API AIR 2.0

AIR 2.0 exposes access to the uncompressed PCM ByteArray data on the Microphone API. You can enable or disable the feature by setting or removing the SampleDataEvent.SAMPLE_DATA event listener on each Microphone.getMicrophone() instance. 

I want to point out that the ability to access the ByteArray in certain APIs has been a long standing request to Adobe, and I will not be surprised if this feature is added to Flash Player altogether in a sub-version of Flash Player 10 or 11. Hopefully Adobe will continue the trend and allow the ability to access NetStream's ByteArray. 

The following application lets you record from any microphone connected.  While you record the audio you can see a bar that shows the volume of your voice as a graphic.  Once you complete recording, you can playback see the a visualization of your recording and save it as a Wave file.

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
                       xmlns:s="library://ns.adobe.com/flex/spark"
                       xmlns:mx="library://ns.adobe.com/flex/mx"
                       xmlns:ui="ui.*"
                       width="470" height="240">
    <fx:Script>
        <![CDATA[
            import com.adobe.audio.format.WAVWriter;
           
            import flash.events.Event;
            import flash.events.SampleDataEvent;
            import flash.events.StatusEvent;
            import flash.media.Microphone;
            import flash.media.Sound;
            import flash.media.SoundChannel;
            import flash.utils.ByteArray;
            import flash.utils.Endian;
           
            import ui.AudioVisualization;
           
            [Bindable]
            private var micNames:Array = Microphone.names;
           
            private var recordedData:ByteArray;
           
            private var mic:Microphone;
            private var sound:Sound;
            private var file:File;
           
            private function onOff():void
            {
                if (recordButton.selected)
                {
                    recordData();
                    recordButton.label = "Stop";
                }
                else
                {
                    stopRecording();
                    recordButton.label = "Record";
                }
            }

            private function recordData():void
            {
                recordedData = new ByteArray();
               
                mic = Microphone.getMicrophone(
micNamesCombo.selectedIndex );
                mic.rate = 44;
               
                mic.addEventListener(SampleDataEvent.SAMPLE_DATA,
dataHandler);           
            }
           
            private function stopRecording():void
            {
                if (!mic)
                    return;
               
               
mic.removeEventListener(SampleDataEvent.SAMPLE_DATA, dataHandler);
            }
           
            private function
dataHandler(event:SampleDataEvent):void
            {
                this.visualization.drawMicBar(mic.activityLevel,
0xFF0000);
                recordedData.writeBytes(event.data);               

            }
           
            private function playRecordedData():void
            {
                recordedData.position = 0;
                sound = new Sound();
                sound.addEventListener(SampleDataEvent.SAMPLE_DATA,
playSoundHandler);
               
                var channel:SoundChannel;
                channel = sound.play();
                channel.addEventListener(Event.SOUND_COMPLETE,
onPlaybackComplete);
               
                visualization.start();
            }
           
            private function onPlaybackComplete(event:Event):void
            {
                visualization.stop();
            }
           
            private function
playSoundHandler(event:SampleDataEvent):void
            {
                if (!recordedData.bytesAvailable > 0)
                    return;
               
                var length:int = 8192; // Change between 2048 and
8192
                for (var i:int = 0; i < length; i++)
                {
                    var sample:Number = 0;
                   
                    if (recordedData.bytesAvailable > 0)
                        sample = recordedData.readFloat();
                   
                    event.data.writeFloat(sample);
                }
            }
           
            private function save():void
            {
                file = new File( );
                file.browseForSave( "Save your wav" );
                file.addEventListener( Event.SELECT, writeWav );
            }
           
            private function writeWav(evt:Event):void
            {
                var wavWriter:WAVWriter = new WAVWriter();
                var stream:FileStream = new FileStream();
               
                // Set settings
                recordedData.position = 0;
                wavWriter.numOfChannels = 1;
                wavWriter.sampleBitRate = 16;
                wavWriter.samplingRate = 44100;               
               
                stream.open( file, FileMode.WRITE );
               
                // convert ByteArray to WAV
                wavWriter.processSamples( stream, recordedData,
44100, 1 );
                stream.close();
            }        
           
        ]]>
    </fx:Script>
   
    <mx:ComboBox id="micNamesCombo" dataProvider="{micNames}"
x="283" y="8"/>
    <mx:Button id="recordButton" label="Record" toggle="true"
click="onOff()" x="28" y="7"/>
    <s:Button id="playButton" label="Play Recording"
click="playRecordedData()" x="102"  y="7"/>
    <s:Button id="saveButton" label="Save" click="save()"
x="208" y="7"/>
   
    <ui:AudioVisualization id="visualization" y="100" />
   
</s:WindowedApplication>

To learn more about this feature and more order AdvancED Flex 4