When we talk, we are using our chest voice. If you put your hand on your chest and talk, you can feel the sound vibrations. The higher in pitch you go (try talking like a whiny baby), you should feel the vibrations leave your chest and resonate in your nose, eye and top of your head area. I get amazed sometimes when I meet people who can’t find their head voice because they’ve never tried to find it before, and they don’t know the feeling or how to get it. Then when they finally do use their head voice, it is usually very airy and weak at first because the vocal cords have never produced these sounds before. Getting to know your “head voice” and exercising it is a good good first step to getting in the mix.
The mixed voice is simply that…a mix of chest voice and head voice. Some singers will have more chest voice in the mix, while others may have more head voice in the mix. You may find these variances in the style of music they are singing. Belt singers like Celion Dion, Aretha Franklin, Barbra Striesand, Adam Lambert, for instance have a strong chest mix that they can produce and carry up through their bridges. Classical singers are most likely to have a stronger head voice in the mix allowing for a more even, balanced sound.
Regardless of your preference of style, exercising the chest, mix and head voice in the proper way is crucial to developing a strong healthy voice.