In physics it is called a transformational event; moving from one level of functioning to a higher (or lower) efficiency level. This is possible when we sing. There are levels of efficiency and effectiveness that most of us never find ourselves, or if we did find it once, we can’t reproduce it at will.
The process of singing is the same process as speaking. And what is called ‘placement’ is central to discovering your actual vocal instrument, versus your pseudo, or false, instrument. And many singers use that pseudo-instrument all the time and when they do it is not their true instrument nor their real self.