Webdrawer does not support the playing of audio files, instead you will get an error message when you preview a Record with an audio file attached.  This can be remedied by adding some HTML to the preview template. To do this, in your Webdrawer install folder:

Open the file '\Views\WDRecordPreview.cshtml'  in a text editor

Add the following HTML

if (new string[] { "MP3", "M4A", "WAV", "OGG" }.Any(ext => ext == record.Extension.Value))
{
    <audio preload="auto" autobuffer controls>
        <source src="~/Record/@record.Uri/file/document?inline=true" />
        <p>Audio playback not supported in this browser.</p>
    </audio>
}
else

Your HTML should end up looking like this: