In the whole crackling realm of electronic tomfoolery, no one has invented any gadget quite so commanding, and quite so overwhelming, as that little machine that answers telephone calls.

In a few brief years, these devices have gone from being mere laboratory curiosities to being must-buy items for every well-run house or office. In the process, they have transformed our arts of verbal communication (which already were quite frail enough) beyond recognition.It scarcely matters whether we consider the machine's Outgoing Message (the one you record yourself before leaving the house), or the Incoming Messages (the seemingly endless stream of trivialities, computerized sales pitches and obsolescent bits of data that clog most machines). Either way, most people, faced with the challenge of speaking into a recording device grow intensely self-conscious.

No one is immune. An Ivy League professor I know, who is a prolific author and frequent guest on television programs and op-ed pages, acquired his first answering machine some months ago. The machine left him mesmerized by stage fright and he was reduced to nervous gibberish.

When you place a call and realize - too late! - that you're about to talk to a machine, one can quickly hang up and forget the whole thing. But this defeats the purpose of having answering machines in the first place.

The idea of speaking for the record brings out the orator in many people. Even when delivering the most routine messages, callers tend to clear their throats, enunciate with rare clarity and speak in complete sentences.

Since they don't want to cough in the middle of a sentence, or have their voices sound squeaky, these callers seem to take deep breaths, as though reciting their elocution lessons in some distant, long-ago Victorian classroom.

The prospect of speaking into an answering machine can turn some normally reticent callers into windbags. Had they reached a live ear, they would be brief and to the point; but when they hear a machine click on, they feel free to drone on about spring training, cocoa futures or whatever happened to Amelia Earhart.

Or they decide to while away some time - your time - by treating you to their latest joke. Or they decide that your tape machine gives them a good time to share gossip about a sick friend. Through all of this, you, the poor listener, find yourself waiting numbly through several minutes of such chit-chat, only to learn that the caller has forgotten why he called.

Mumblers, however, are the worst. Whether these people mutter through a folded handkerchief, I don't know; but they inevitably garble the most critical part of their message - the time of an appointment, say, or a return telephone number - and then the machine is worse than useless.

At least with a human voice speaking on the other end of the wire, you can ask it to repeat. A telephone answering machine never gives you that second chance.