The dynamics of hearing when it comes to our own voices is just rudimentary biological anatomy.  When we hear our voices as spoken, our hearing picks up the sound from an internal source as opposed to an external environment.  Thus, when listening to a recording, we sound quite different and unrecognizable.  We are put off by it. 

On the other hand, the art of communication is a skill that needs proper training and development.  You can teach yourself to speak clearly and concisely by picking up a book and read select passages slowly and deliberately.  Pause to pronounce each word correctly; be mindful of all unsilent vowels and consonants.  A forceful voice is not generated by your vocal cords as you would think.  Learn to breathe with your abdomen, not your chest.  That is the source of vocal range.  Relax the throat muscles when speaking, tightening only constricts the air passage and blocks natural air flow. 

And keep in mind, there are 2 progressions of speech:

1. Natural dialog between individuals and friends
2. Exaggerated speech as in acting and public speaking.  These are rehearsed, orchestrated vocal mannerisms delivered in premeditated form paying special attention to specific pronounciation and inflection.  This is what you need to successfully develop.

Breathing, deliberate pronounciation, and timing.