I think the NullRingtone class should go in a file of its own. If you do that, then everything else in this file is related to how ringtones and alert tones are stored in the settings db.  So this isn't really a utils.js file. It is the module that encapsulates everything about how ringtones are set and queried. I recommend you define a RingtonesSetting class or singleton and name the file ringtone_settings.js.  (Or maybe you can come up with a better name... CurrentTone.set(type,tone), CurrentTone.get(type), etc.)