South Korean consumer-electronics company LG has denied allegations that its smart televisions record ambient conversations, listen while on standby and store recordings for later transmission.

On Wednesday, the company told Al Jazeera that voice data is only recorded when a user presses and holds the voice button on the TV remote or activates its “Hi LG” wake word, after the user has activated the Far-Field voice recognition feature.

“Other than these instances, the TVs do not collect or record ambient conversations,” LG said, adding that voice data is only processed via explicit user commands.

“The audio is immediately deleted if the wake word is not recognised,” the company said.

The statement comes after a 135-minute investigative report released on Monday by a popular tech media outlet and YouTube channel, Gamers Nexus, with Level1Techs and independent security researchers. The investigation examined LG televisions’ data collection and security systems, raising questions about how the devices handle users’ private information.

By analysing network traffic and software, the researchers purport to have discovered that these televisions actively track users and harvest a glut of local network data, including audio transcripts.

Inside LG’s controversial tracking system

Gamers Nexus said its researchers were able to record audio through an LG television while it was in a state of hibernation, meaning that even if the microphone switch on the TV is turned off, other microphones exposed to the TV might not be, such as the remote.

The result, Gamers Nexus says, is “216,000,000 Spy TVs” in the US alone.

On its website, LG says it has 49 million smarts TVs in the US and 216 million globally.

Recorded background noise in the room, including as far as 12 metres (40 feet) away from the TV, was also being archived, they said.

Yash Vekaria, a computer science researcher at the University of California, Davis, says that because TVs stay in homes for years, often past their update support, “prompt patching from LG matters”.

“This vulnerability can allow sniffing [of] much more critical conversations … Imagine government officials discussing national security in their hotel room [next to an] LG TV”, Vekaria said.

The researchers further alleged that unmatched wake-word interactions or unclear sounds could remain stored locally, transcribed and preserved on the device as plain text in case the local network is disconnected and uploaded later to LG servers.

Copies can stay in temporary storage spaces, known as buffers, without the user knowing, Vekaria said.

Privacy risks generally stem from poor design and selective disclosure. The more disconcerting threat lies in a compromised device, Vekaria added, which could be made to execute any command its hardware allows. 

The researchers also said they found text transcripts derived from audio captured by the television, even after 10-15 seconds of silence after invoking “Hi LG”.

The claims have not been independently verified by Al Jazeera.

“It raises a question of purpose,” says Vekaria, “a voice command is only useful in real time, so audio queued for later upload is presumably being kept for something else, such as logging, analytics or model training. LG should explain what”.

Vekaria says he is not aware of any concrete evidence that ambient audio or transcripts feed into LG’s advertising or profiling systems.

“What we do know is that LG runs an advertising business built on household data, including the Automatic Content Recognition [ACR] tracking documented in our research, and that its voice pipeline appears to capture and retain more than users would expect.”

Still, there may be simpler explanations, he says, “such as diagnostics or improving speech recognition … but even those involve keeping recordings from people’s homes without meaningful consent”.

The smart home is listening 

The researchers also said that the televisions scanned home networks for other devices and collected information including internal IP addresses, nearby Wi-Fi networks and location data.

LG said scanning for nearby devices is a “standard” smart-TV function.

Device discovery can serve “legitimate functions” such as screen casting, media sharing and connecting smart-home products, like Amazon’s Alexa, said Anna Maria Mandalari, a lecturer in communications and networking at University College London.

LG stated that ACR, voice recognition and interest-based advertising are all “separate features”, each requiring “explicit user opt-in consent” and each of which can be disabled through the TV’s settings.

Depending on how device discovery is implemented, Mandalari said, a television may “obtain the names, addresses, manufacturers and types of other devices on a household network” – information that can reveal the composition of a home and help “create a broader profile of its occupants”.

LG’s advertising arm, LG Ad Solutions, has openly marketed the breadth of information it can derive from connected households. Corporate videos featured in the Gamers Nexus investigation show LG representatives saying: “We know who is in the LG household,” and, “We know which devices are there.”

LG told Al Jazeera that it was “committed to providing transparency” and that it rejected “deceptive practices”.