If you use a program like Audacity to record you can do pitch changes of your voice to pass off as higher or lower than you are. If that's what you're worried about. If you're worried about people recognizing you, Audacity covers that too xD

Listening to yourself recorded can be really jarring... I'm fairly used to it since I've done auditions and what not like this in the past (my voice sounds so much higher recorded) the best thing for it is just to record and listen to yourself a lot, and you may want to do that anyway so you make sure it sounds allright to you. Hey if anything perhaps another person would come forward willing to voice for you :3