We seldom hear our true voice when we speak or sing. The first time we listen to a recording of ourselves, we go into denial that goes something like this. "That isn't my voice. I don't sound like that. There must be something wrong with the recording device. Wow! I'll never sing again!"
What we hear when we speak or sing is not our true sound. As we grow from babies to adulthood we think our vocal sound is true, but it isn't and here's why.
Sound reaches the inner ear by way of two separate paths, and those paths, in turn, affect what we perceive. I like Matt Soniac's description of this process:
"Every sound we hear—birds chirping, bees buzzing, people talking, and recordings—is a wave of pressure moving through the air. Our outer ears “catch” these waves and funnel them into our head through the ear canal. They strike the eardrum, which starts vibrating, and those vibrations travel to the inner ear, where they’re translated into signals that can be sent via the auditory nerve to the brain for interpretation.
When you speak, vibrations from your vocal cords resonate in your throat and mouth, and some get transmitted and conducted by the bones in your neck and head.
This combination of vibrations coming to the inner ear by two different paths gives your voice (as you normally hear it) a unique character that other, “air only” sounds don’t have. In particular, your bones enhance deeper, lower-frequency vibrations and give your voice a fuller, bass-like quality that’s lacking when you hear it on a recording."
You have a big vocal range which is why you can sing both low and high. Be happy about this.
Singing is an extension of the speaking voice. It's rare that a singer speaks in just one pitch. Try singing scales for 15 minutes each day to help your speaking voice.