NEW YORK (CNN/Money) - It doesn't know your name, your telephone number, or even what size you wear, but this window can still get your attention by one little whisper ...."Hey, we have a sale in here. Come on in."

It's called a Whispering Window, a new audio system from Ames, Iowa-based Etrema Products, that can transform a retailer's storefront window, walls, tables and mannequins into speakers that emit sales pitches to passersby.

Observers say retailers are focusing more on innovative technology such as Whispering Windows and digital displays as a means to differentiate themselves in a highly competitive and mature industry.

"This is specially true of the specialty stores," said Howard Davidowitz, president of New York-based retail consultancy Davidowitz & Associates. "Retailers have to become more creative if they want to keep customers longer in their stores and if they want them to keep coming back."

Whispering Windows, which costs about $1,750 per window, is made up of two small attachable chrome discs, about the size of a hockey puck, that connect to any audio source such as a portable music system.

But unlike regular speakers, the system's unique technology allow solid surfaces such as glass, steel, plaster or wood to produce sound in the form of spoken words, music or both.

"It's the similar technology used by the Navy for sonar applications," said Joe Carswell, spokesman for Etrema. "We're just applying it in a different scenario."

Said Carswell, "It works in two ways. Either the store can have one message playing constantly or it can be set with a motion sensor so that the audio is activated when someone walks past it."

Etrema debuted the device early this year to the U.S. retail industry and it's already generating plenty of buzz, Carswell said.

Impart's counter-top mirrors feature built-in LCD screens and hidden speakers.

"We can't talk too much about who has approached us about Whispering Windows, but we have spoken with Macy's West, it's already in Nintendo stores and we're also talking with some of the big apparel chains," he said.

According to a recent industry report, Borders (BGP: Research, Estimates), the nation's second-largest bookseller, is testing digital signage at a few of its locations -- including its Time Warner Center store in New York, where 42-inch plasma screens are located throughout the stores.

"Digital signage is great because it can be centrally controlled and updated," said Edwin Reger, vice president of business development for Impart Inc., a Seattle-based provider of digital media solutions.

"Retailers don't have to worry about whether the store staff is updating the signage at the right time or with the correct ad," Reger said. "The moving colors and animations also make the displays more entertaining for shoppers."

The Borders storefront in New York's Time Warner Center displays multiple digital displays.

If fun and games could boost sales, retailers should be thrilled with Impart's latest creation called Video Reflections. These are 11 different models of mirrors that cost about $2,000 to $3,000 each and contain built-in videoscreens, a hidden speaker.

A new prototype of the mirror even sprays perfume.

"It has a surprise element to it combined with a 'Wow! Look at me!' factor. Each system is entirely self-contained. All that the salesperson has to do is plug it in," Reger said, adding that Neiman Marcus already is using the interactive mirrors in its stores and the company's in talks with some other high-end department store chains.

The question, of course, is whether or not these devices will help ring up sales at the register.

"All these new gimmicks are very interesting but the jury's still out about their impact on the consumer or if they'll be cost-effective in the long run" George Whalin, an independent retail consultant. "People don't shop at a store because of one thing but a combination of factors. Even if shoppers like the fancy technology, a rude employee can turn them away from the store."

Macy's could not immediately be reached for comment on the story. Neiman Marcus and Borders did not return repeated calls for comment.