The importance of voice modulation.

Professional speakers are like actors on stage, they perform to sell an idea or product to their audience with their voice, facial expression and gestures.  They demonstrate their enthusiasm with showmanship not just by reading their speech or delivering a carefully memorized one, but in a passionate rendition that will trigger the same response from their audience.

In public speaking, it is the voice that should be most of all commanding.  It should be clear and loud enough to be heard by the farthest of audience in the room or hall where you are speaking. Nothing is more frustrating for an audience than having to strain their ears to hear a speaker who whisper, mumble or stutter and having to pucker their foreheads to try to understand their perplexing diction.

Practice delivering your speech before the actual presentation and record it and listen to yourself.  If it is not what you would like to listen to, then improve on it. Practice more, aim to be understood clearly, pronounce your words well and pause to stress a point. 

Not all great speakers are born with great voices, but they learned to improve their voices by vocal exercises  and  constant practice.  So, follow what they are doing,  rehearse often and exercise your vocal chords  to make your voice come out loud and clear, then learn how to modulate to make it pleasing to your audience’s ears.