The speech opening, "Hello everyone..." is like an institution. But, I would argue that it's an institution that should be shown the door because it detracts from the speech that follows. More specifically, when a speaker addresses everyone, she (or he) addresses no one. And, if members of the audience feel they're being lumped together with everyone else in the room, they're going to feel less of a connection with the speaker.

When you address a group this way, it implies you see a featureless group, rather than a gathering of individuals. "Hello everyone..." and "Thanks everyone..." and their variations depersonalize the audience. For those of us in the audience, it seems to suggest you're speaking past us, to some unknown at the back of the venue.

The same audience response is true, to some extent, of the phrase "Ladies and gentlemen" although its long history implies formalism rather than depersonalization.

You might well object, though, that many speakers and entertainers use the speech opening phrase, "Ladies and gentlemen...". And, you'd be right. They do. Talk-show host, David Letterman, for example, often prefaces his jokes or anecdotes with the phrase. In that case, the phrase is likely not a bad habit; it's probably done intentionally. By using "Ladies and gentlemen..." he adopts a formalism that contrasts very effectively with his off-the-wall style of humor. The contrast between the two makes the jokes more enjoyable.

Similarly, some very good public speakers also use this speech opening intentionally. Once more, the idea is to sound formal, but now it's used to provide emphasis, rather than contrast. Prefacing a key point with the "Ladies and gentlemen..." orally underlines the words to come, and gives them greater emphasis than the other words.

One last note: Sometimes speakers and entertainers use the phrase unintentionally because of misguided advice or old habits. They haven't enjoyed good, detailed critiques that would expose the usage.

While I can find reasons to use "Ladies and gentlemen..." I can't find one for "Hello everyone..." or "Thanks everyone..." Both speech openings depersonalize the audience, which lessens the effectiveness of a speech or presentation.

And what, you might ask, should we do instead? Well, if you speak to a group, whether formally or informally, start by thinking of the group as a collection of individuals, each of whom wants to be addressed personally in the speech opening. Keep in mind that old marketing acronym, WIIFM, "What's in it for me?" It's a way of reminding ourselves that every individual in an audience has his or her own wants and needs, starting with recognition of their existence.

And, that can be done quite simply. If you say simply "Hello..." rather than "Hello everyone..." makes it possible for each individual to assume that the greeting is being directed to them, and just them. The same applies to "Thank you..." and other usages.

I also find it works well if you pause after saying a simple "Hello" and then make eye contact with a number of people in the audience. You don't have to make contact with everyone, but at least a few.

Wrapping up our exploration of speech openings and audience responses, never speak to the group as if were an undifferentiated group; always address it as a collection of individuals. Bottom line: avoid both "Ladies and gentlemen..." and "Hello everyone..." (and similar speech opening variations) unless you have good and specific reasons.