Call it the "Siri effect." With Apple expected to unveil on Wednesday a new iPhone with added capabilities for Siri, its voice-activated digital assistant, industry experts say two factors are driving an explosion of voice-enabled services in smartphones, televisions, cars and other consumer products.
One is technological, as increasingly sophisticated software taps into vast amounts of data processing power over the Internet, to augment the computer chips inside a phone or other gadget. The other is based on the popular appeal of Siri and its rivals, boosted by an extensive Apple ad campaign with celebrities Samuel L. Jackson, Zooey Deschanel and Martin Scorsese.
A number of tech companies - including Google, Microsoft and IBM - are working on voice technology. But "Apple's introduction of Siri, combined with their marketing, has really had an impact in creating consumer expectations," said industry analyst Dan Miller of Opus Research.
And as more consumers see what the technology can do - even if imperfectly and not all the time - their expectations are fueling demand that's forcing product manufacturers to embrace the technology, said Mike Thompson of Nuance Communications, a leading supplier of voice-computing tools to other companies including Apple, Ford and Samsung.
"We've been steadily growing for a number of years, as speech functionality on devices has been improving. But we've recently crossed a threshold of consumer awareness," said Thompson, an executive vice president at Massachusetts-based Nuance, which makes software that helps computers recognize voice commands, parse them into tasks or processes, and convert digital results into human-like speech.
In recent years, Google has introduced voice-activated navigation, search and translation apps based on technology that it developed internally and through acquisitions. But with the debut of Apple's Siri last year, the tech rivals are now engaged in a high-profile voice-technology arms race.
Some analysts say Google regained the lead this summer when it added more voice capabilities to the Android mobile software that powers smartphones made by several iPhone competitors. But Apple has touted new features in the latest upgrade of its mobile software, which will power the new iPhone 5. According to Apple, Siri will soon be able to launch applications and use services like OpenTable to make a restaurant reservation with voice commands.
Microsoft has also added voice capabilities to its smartphone software as it vies for a share of the mobile market now dominated by Apple and Android. In addition, Microsoft has introduced voice commands for its Bing search engine and Xbox entertainment console.
Meanwhile, Ford and other automakers are incorporating voice technology into navigation systems, climate systems and music players, while Samsung, LG and Panasonic are shipping television sets with voice controls.
Younger motorists want their cars to do more than provide transportation, according to Ford executive Sheryl Connelly, whose company has worked with Nuance and Microsoft. Internet connectivity allows motorists to send messages and get information, she said during a talk sponsored by Silicon Valley's Churchill Club, while voice controls can "simplify those interactions" so drivers don't get distracted.
Voice controls are becoming so common that car companies must decide whether to let their systems interact with the gadgets motorists carry in their pockets, Miller said. Apple has announced it's working with General Motors and others to build a Siri voice-command button into car steering wheels.
Not far in the future, some experts foresee other voice-activated appliances and home systems that control thermostats and alarms. Already available are programs that use a person's unique voiceprint to determine if he or she is a gadget's rightful owner, and thus authorized to access data or make online purchases.
Even Siri's fans will concede that today's voice systems are far from perfect: Internet connections can be lost. Programs stumble on unusual phrases or figures of speech, and they generally can't offer more than pre-programmed quips in response to abstract questions like, "What's the meaning of life?"
Today's voice technology works better within limited areas, such as automated call-center programs that can recognize questions and provide answers relevant to a specific company or industry - rather than confronting a much wider range of queries like Siri does. But experts also say the expanded use of voice services will provide even more data that engineers can use to improve the way computers recognize and respond to spoken commands.
At the Churchill Club event, veteran computer scientist Ronald Kaplan compared the evolution of voice technology to the speech development of a child.
Talking with computers was once as limited as speaking to a toddler, said Kaplan, who worked on voice technology at Xerox PARC and Microsoft before joining Nuance. Today it's more like talking with a 5- or 6-year-old, he added, and "the conversation is getting kind of interesting."
Explore further: Technology to help people with disabilities to learn and communicate