SAN FRANCISCO — Like a lot of teenagers, Aanya Nigam reflexively shares her whereabouts, activities and thoughts on Twitter, Instagram and other social networks without a qualm.

But Aanya’s care-free attitude dissolved into paranoia a few months ago shortly after her mother bought Amazon’s Echo, a digital assistant that can be set up in a home or office to listen for various requests, such as for a song, a sports score, the weather or even a book to be read aloud.

Anjana Agarwal, left, hasn’t been able to find the Echo device hidden by her 16-year-old daughter, Aanya Nigam, who feared her privacy was being compromised. The Associated Press

After using the Internet-connected device for two months, Aanya, 16, started to worry that the Echo was eavesdropping on conversations in her Issaquah, Washington, living room. So she unplugged the device and hid it in a place that her mother, Anjana Agarwal, still hasn’t been able to find.

“I guess there is a difference between deciding to share something and having something captured by something that you don’t know when it’s listening,” Agarwal said of her daughter’s misgivings.

The Echo, a $180 cylindrical device that began general shipping in July after months of public testing, is the latest advance in voice-recognition technology that’s enabling machines to record snippets of conversation that are analyzed and stored by companies promising to make their customers’ lives better.

Other increasingly popular forms of voice-recognition services include Apple’s Siri assistant on mobile devices, Microsoft’s Cortana and the “OK Google” feature for speaking to Google’s search engine. Spoken commands can also be used to find something to watch on some TVs, and an upcoming Barbie doll will include an Internet-connected microphone to hear what’s being said.

These innovations will confront people with a choice pitting convenience against privacy as they decide whether to open another digital peephole into their lives for a growing number of devices equipped with Internet-connected microphones and cameras.

The phenomenon, dubbed the “Internet of Things,” promises to usher in an era of automated homes outfitted with locks, lights, thermostats, entertainment systems and servants such as the Echo that respond to spoken words.

It’s also raising the specter of Internet-connected microphones being secretly used as a wiretap, either by a company providing a digital service, government officials with court orders or intruders that seize control of the equipment.

“We are on the trajectory of a future filled with voice-assisted apps and voice-assisted devices,” Forrester Research analyst Fatemeh Khatibloo says. “This is going to require finding the fine balance between creating a really great user experience and something that’s creepy.”