making voices sound similar

Hello, I am new to the forum.  I figured that a place like this would probably get me the best answers on my dilemma.  In a nutshell, here is what I am trying to do.  I am working on a home automation project that will use voice recognition technology to allow me (and hopefully others) to be able to speak to the system and have it respond.  The issue is that with speech recognition in windows, you typically have to train a profile to a specific person.  What I am wondering is if there is a vocal processor of sorts out there that can take 2 (or more) different voices and make them sound similar through the same microphone.  Basically if I say something to the system, and then hand the microphone to my wife or a friend, I would like the resulting voice that gets fed to the computer to sound similar enough that the speech recognition software can still think it is the same person.  I do realize that trying to do this with people with extreme differing voices (one bass sounding voice and one high pitched voice) that this would be more difficult.

I am at the starting stages of the audio setup for this.  Currently I have a good gated Shure SCM-810 auto mixer, and plan to get some Crown PZM series (PZM-10 or PZM-11) microphones.  If I can feed the output of the SCM-810 into the vocal processor before sending it to the computer, that would be the preferred method.

Any help on this would be appreciated.