The "voice" of a particular preacher ought to be subject to the ears of those to whom they have been sent. Preaching is not about the voice of the preacher but rather the hearts of the listeners to whom God has sent his Word. If I am preaching to a group of prisoners my "voice" will sound different than it does to a group of business people. In the same way that the Apostle Paul became all things to all people that he might save some, so too must the preacher.
Any given Sunday the preacher is called to be a teacher, a prophet, an evangelist, an exhorter, or an empathizer. Which one depends on what God is up to with a particular people. And to be the right one at the right time the preacher must first listen to the text and the Spirit before he imagines what it will sound like when he opens his lips. One's voice must become subject to the context of their calling.
We are not artists that choose our subject matter or presentation of it based on our whim or passion. If we do not die to ourselves before we step into the pulpit then we may have found "our voice" but have done so at the expense of the Word. Lord, save those to whom you have sent me if it is my voice they hear.