Yes. This article was originally going to be titled "Silent But Deadly," but then I realized many of my readers would be aghast at my lack of judgment and taste. Puns are entertaining, but on a serious note, utilizing a well-modulated soft, unwavering voice [the proverbial 'whisper in someone's ear'] is one of the most powerful ways to make your words carry serious intensity.
In individual cases (one person to another), it makes the information seem that much more important. In group cases (where you are speaking to a crowd or lecturing or presenting to a group), it forces your audience to be stock still, to strain to hear your every measured syllable, to focus on what you are saying (and tune out all other distractions, almost hypnotically), and to give every one of your words more impact. Your audience will generally lean forward in order to hear you more clearly. This is reflexive behavior.
Sotto voce, Italian for "soft voice" is always interpreted by the Human Subconscious and social conditioning, as foreshadowing a shared and important secret. It is a tool that few military-trained or public speaking-trained learn how to master... or even to use effectively.
If you gently make bodily contact (in an individual-to-individual case, where you gently touch the other person's shoulder or forearm, you will anchor the content of your message more deeply by the added element of associative touch.
The cliche is that "Silence is golden" (and it may well be in an interrogation), but do not forget, to paraphrase an old aphorism, when you speak softly, you automatically carry a big stick.
Douglas E Castle for The Sending Signals Blog.
Please also look at The Taking Command Blog, too. Thanks.