Marketers have learned one very important thing in recent years. What's that? Well, that buyers are liars. More to the point, buyers can't tell you the truth because the truth eludes even them. With this insight, Procter and Gamble turned the Swiffer into a phenomenally popular cleaning item. They didn't ask their customers want they wanted in a cleaning tool; they observed their behavior.

Well, you don't just have to observe anymore. Now, you can listen. The human voice is more revealing than we ever knew.

That's what wireless services company Nextel has discovered. "A customer can say they’re satisfied with a product," says John Tidwell, director of primary market research for Nextel. "But until now, we’ve had no real way of knowing the truth."

Nextel is using Layered Voice Analysis (LVA) to analyze customerr conversations and derive key marketing insights. LVA leverages mathematical algorithms to assess voice frequencies and identify levels of stress, deception and enthusiasm. The technology, which was developed by the Israeli firm Nemesysco for security uses, promises to make important contributions to the field of customer intelligence.

What Nextel found is that the technology can be used to analyze customer responses to brand extensions and gauge levels of overall product satisfaction. One focus group recently revealed their dissatisfaction with a product through their narratives. "They could not articulate what was making them upset, so they created scenarios to help quantify their feelings," Tidwell says.

Such insights are helping Nextel refine its offerings to strengthen customer relationships. "It’s amazing marketers haven’t gotten into this in a deeper way yet," he says. "But when they do, a lot about marketing and its capacity is going to change."