This is up to your DM
The rules do not further elaborate what is meant by "your voice". This answer argues anything that you can produce as sound is "your voice". I think it is not as clear cut.
By necessity for any sound you utter, you must use your speech apparatus, including to mimic another voice, so you could argue that it just does not sound like your voice while it still is, but I think that is sophistry. It is not even clear what the "in your own voice" clause is doing, if any sound you can utter anyways is your own voice. If you interpret anthing you can produce to be your "own" voice, the clause does exactly nothing.
I think this is not about how you generate the voice, it is about what it sounds likesounds like.
You can speak louder or less loud in your normal voice, or you can maybe even have different sounding voices in differnt languages, or speak higher or lower, depending on how threatening or excited you feel. But typcially, a persons voice is recognizable as that persons voice, and you can make out who is speaking just by "their voice".
5e is meant to be read as idiomatic English, not as a physics or biology simulation. WhenAnd when you have a bad cold, you say "My voice is gone", even though you can still audibly speak, using your vocal chords.
5e is meant to be read as idiomatic English, not as a physics or biology simulation. When you imitate another person's voice, in normal English one would not say that you speak in your own voice. So, when you make up or mimic another voice, you may be using your vocal apparatus, likewise you arebut not speaking in your own voice.
It is not even clear what the "in your own voice" clause is doing, if any sound you can utter anyways is your own voice. As you are speaking, if you interpret anthing you can produce to be your "own" voice, the clause does exactly nothing.
So I think that the reason the clause is there is exactly to limit presntingpresenting the voice as not yours. But, in the end, there is no explict defintiondefinition of what this means, so this is the DMs job to decide.