You may notice a slight lisp as you adjust to wearing your aligners, since they’ll be forcing your tongue to adjust to changed spaces in your mouth. And because you hear a different resonance in your voice than everyone else does — think about how different your voice sounds on a recording — you might still feel like you have a lisp after that. But no one else will notice any difference in your speech after a few days, and they won’t know you have aligners in unless you tell them.