When Archie McDaniel walked into the Chief Auto Parts store in Gardena in Southern California the other day, all he wanted was some STP oil treatment for his overheated car.

But while he walked down the store aisle, his body motion was quickly detected by an infrared device that suddenly blurted out a message - first in English and then in Spanish. The message asked him to purchase a bottle of Turtle Wax. He didn't."I don't care what the machine says," said McDaniel, a production assistant for a Los Angeles film production company. "The best thing that they can do to sell Turtle Wax is to drop the price."

But if some advertisers have their druthers, an array of "hidden voice" product promotions, such as this one, may be the sound wave of the future. This same infrared device has been tested - with some success - at several supermarket chains.

Another manufacturer has also found a way to put a human voice onto a computer chip that will soon be placed inside mailed advertisements - and perhaps even be tucked into some magazine advertisements within the next year.

Suppose you opened up Time magazine, and out of nowhere, some silicon-chip-of-a-voice suddenly tried to sell you Scotch?

"Most grocery shoppers aren't sure what they want," said Mort Gleberman, vice president of marketing at Los Angeles-based Ladd Electronics, which manufactures the Soundtron shelf talker. "But if you're rolling past the Campbell soup, and just then a message tells you that Campbell soup is on sale, it could coax you to buy it."

Well, maybe. But one advertising research specialist worries about overexposure. "What if you were grocery shopping and every can of something started shouting `Buy me'?" said Arnold Fishman, chairman of the Los Angeles marketing research company, Lieberman Research West Inc.

But that was hardly the case earlier this year, when a Boys grocery store test-marketed the shelf talker on nine different products. Shoppers who walked by these products, which ranged from chili to pancake syrup, suddenly heard 16-second spoken advertisements. Eight of the nine products located by the talking ads showed substantial sales jumps.

Still, Boys isn't sold on them. "Some customers objected to that kind of advertising," said Rick Kester, vice president of merchandising at Boys Market Inc.

And several customers at Chief Auto Parts told Calvin Jackson, the store's assistant manager, that they were also frightened by the sudden voice ads. "One customer even told me that she thought it was God talking," said Jackson.

Similar unexpected advertising chatter may soon be spewing out of your junk mail - and even in magazine ads.

Behind all this is a tiny, talking gadget called MailCall. And behind MailCall is a joint venture of Structural Graphics, an Essex, Conn.-based manufacturer, and Electronic Speech Systems Inc., of Emeryville, Calif. They make a tiny computer chip encased in a one-inch "speaker" that can be placed inside brochures or advertisements.

The biggest problem is the high cost - up to $4 per unit. "It is very, very expensive," said Richard

McEvoy, senior vice president of marketing at Carillon Importers, which imports Absolut Vodka into the United States. For several years, Absolut has been regarded as an innovator in print advertising, and two years ago it produced a magazine print ad with a computer chip that played a Christmas carol. "I predict you'll see talking ads in the next year or two, but not until these things are more cost efficient."

But the manufacturer says that talking ads will be in consumer magazines within the next year. "This is just the beginning," said Chris Crowell, president of Structural Graphics.