Why it matters: While smart speakers continue to make their way into more households, there's increased concern that our recorded conversations could be heard by strangers. Those fears won't be helped by the admission of a former Amazon executive, who says he turns off his Alexa smart speaker whenever he wants a "private moment"

Robert Fredrick, who was once a manager at Amazon Web Services, told the BBC's Panorama program that he always turns off his Alexa speaker when discussing anything private or sensitive.

"I don't want certain conversations to be heard by humans," he said. "Conversations that I know for a fact are not things that should be shared then I turn off those particular listening devices."

Alexa has been known to mishear wake words in conversations and start recording them without participants' knowledge.

In April last year, it was reported that Amazon employs thousands of contractors and full-time workers around the world to listen to voice recordings captured by Echo devices. The conversations were transcribed and annotated with the aim of improving the performance of digital assistant Alexa, helping the AI better understand human speech. Amazon said less than one percent of conversations are listened to by human staff, and the information is anonymized beforehand.

Following criticism of the annotation program, Amazon introduced an option that allows users to opt-out of human review of their voice recordings. You can also delete most of your transcripts stored on the company's servers.

Fredrick wasn't the only ex-Amazon worker with concerns over Alexa speakers. James Marcus, a senior editor at Amazon between 1996 to 2001, said: "I simply hate the idea of voluntarily putting a bug into my living room, and knowing that some schmo in Seattle might be listening to it on a headset."

In response to the program, Amazon asked why Panorama would choose to question a former worker who left long before Alexa was created. "It is surprising that someone who left Amazon 14 years ago is being quoted, about a technology that was developed a decade after he left. His quotes do not accurately portray how Alexa works," a spokesperson told The Sun.

"We take privacy very seriously at Amazon and designing Alexa was no different. Echo devices are designed to detect only your chosen wake word. No audio is stored or sent to the cloud unless the device detects the wake word. Customers can review and delete voice recordings at any time in the Alexa App, as well as, choose to have them automatically deleted every 3 or 18 months on an ongoing basis."