Head voice or chest voice? Potato potaaaaato? Or are they all part of what goes into making you sound like, well, YOU.
Most of us are familiar with the terms 'head voice' or falsetto and 'chest voice' or belt. Chest voice has a more loud or intense quality, one that we tend to use for speech which is why it is sometimes described by students as their 'normal' voice. Head voice is more widely associated with a more classical sound and for many it is deemed as a quieter or weaker one. Mainly because it may have been undiscovered or under used.
So do we have two completely different voices? The answer is no.
The reason they may feel like two completely different voices is because in order to move up in pitch you need to change the position of the larynx and also engage different muscles.
Here comes the science:
For your chest voice your vocal folds are thick and short and are attached to a muscle called the thyroarytenoid, or TA, which stretches across the windpipe and causes sound as the air passes through them. (Think of your vocal chords like a reed on an instrument.) But in order to raise up in pitch to access those higher notes you need to be able to stretch the chords. (The chords stretch so that the space between them is smaller creating a high pitch. A bit like when you blow over the top of the bottle, the smaller the space the higher the note.) When we are singing in chest and maintain that placement, this is when we feel like we hit a ceiling and cannot go any higher. We need to let what is called our cricothyroid muscles, or CT, take over in order to tilt the cricoid and stretch the vocal folds. Essentially if going up in pitch were a relay race, the baton needs to be passed from one set of muscles to the other and that's why we do singing exercises to make this transition as seamless as possible.
Exercises to help with the transition between chest and head:
A lip trill or lip bubble, or as I sometimes describe as a motorbike impersonation on a scale or siren
Performing a siren through a straw ( See my vlog on Straws!)
So in short:
Really our two 'different' voices are both one and the same voice. I find it is easier to think of the resonance (vibration of the sound) either being placed in the chest or the head and then in terms of your mix voice, quite simply a mixture of the two! It is about the different resonant chambers in the body not different voices!
With help accessing your head voice see my vlog on Extending Your Range!