Antares Audio 21003 Auto-Tune EFX 3 Vocal Effects Processor Powered by the same core technology as Antares' professional standard Auto-Tune 7 Auto-Tune EFX 3 is the quickest, easiest-to-use tool for real-time pitch correction. Auto-Tune EFX 3's new variable Retune Speed and Humanize controls provide an entirely new level of natural, realistic pitch correction.