As Apple’s voice controlled personal assistant technology Siri grows in popularity, search engine giant Google’s chairman and CEO Eric Schmidt feels the pressure. Schmidt admitted to the U.S. Senate antitrust subcommittee that Apple's new Siri is a "significant development" in search and could pose a threat to his company's core business, according to a report by AppleInsider.

AppleInsider reporter Josh Ong wrote that these comments came in the form of a statement to the subcommittee in response to questions from the senators after Google’s September 21^st hearing. It was also reported by Neowin.net. “Schmidt's remarks, however, may be best taken with a grain of salt, as letter's objective is clearly to downplay Google's prominence, while highlighting its competitors,” wrote Ong.

As per the report, the Google executive took special care to call out Siri as a new development that might supplant Google's search engine.Continuing, Schmidt wrote, '"Even in the few weeks since the hearing, Apple has launched an entirely new approach to search technology with Siri, its voice-activated search and task-completion service built into the iPhone 4S," according to AppleInsider’s Ong.

Per Ong’s report, “Schmidt even went so far as to cite two publications for calling Siri a "Google killer" and Apple's "entry point" into the search engine business.”In fact, back in September 2010, Schmidt had denied that Apple and Facebook were a competitive threat, wrote Ong. However, Schmidt admitted, "My statement was clearly wrong." "Apple’s Siri is a significant development — a voice-activated means of accessing answers through iPhones that demonstrates the innovations in search," stated Schmidt.

Furthermore, Schmidt added, "Google has many strong competitors and we sometimes fail to anticipate the competitive threat posed by new methods of accessing information."

AppleInsider wrote that Google competes against search engines like Microsoft's Bing, Yahoo!, specialized search engines, such as Kayak, Amazon, WebMD, eBay, social networks like Facebook, Twitter, commercial software companies like Apple, Microsoft, mobile apps and direct navigation.