Many of us are familiar with the work of Dr. Albert Mehrabian of Stanford University, who demonstrated in his research that 85% of emotion is communicated through voice tone and body language.

Many of us have read Blink, by Malcolm Gladwell, who reported the work of Nalini Ambady of Tufts University, who discovered that some doctors who make serious medical errors are not sued, while some who make no errors are sued.  The cause for both these surprising findings comes down to voice tone: Ambady recorded all her subjects.

Error-free doctors who get sued have authoritative (non-empathetic) tones, while error-prone doctors who do not get sued have empathetic voices.  Perhaps the empathetic tone innoculates the less than competent physician by making patients less willing to damage his career.  (Patients might be thinking, ”He’s such a nice man.”) And likewise, the authoritative tone of doctors without medical errors may annoy patients, who will look for something to get upset about.

Now comes a study testing whether members of a native tribe in Ecuador, who know no English, can understand what English-speaking mothers mean when speaking to fellow adults, and then to their babies.

The answer is mostly yes.  When listening to recordings of the mothers, they identified the correct meaning of the speech to adults 64 percent of the time.  But when the English-speaking mothers talked to babies, they succeeded in grasping the meaning of the speech 75 percent of the time.  The report appears in the August issue of Psychological Science.

Those of us in business seeking to influence and lead others–what can we take away from this?  Most simply, that we might be able to improve the power of our spoken communication (to tribesmen and to our colleagues and customers) with greater expressiveness in our voice tone.

In my experience, some of us are reluctant to explore this aspect of effective communication.  We put more faith in mastering our content and organizing it in a logical manner.

I can only say what many have said before me:  expertise is necessary but not sufficient.   Logic may be the language of reason, but style adds to it life, sentiment, and shading.

The tone of a human voice is often more powerful than the words being spoken.   Ask the doctors whose insurance premiums have gone up.