Google must provide details on Nest microphone error

The Nest Guard contained a microphone, but Google did not disclose that in the product's specifications

US senators have written to Google asking for more details about revelations that a hidden microphone had been built into its Nest devices.

The existence of the microphone was revealed when Google announced that it would be enabling voice-activated features on the home alarm product

The company then apologised for not disclosing the fact earlier, saying it had not been used "up to this point".

Now, senators are asking chief executive Sundar Pichai to clarify.

"In recent years, consumers have become increasingly concerned about the ability of large technology companies to collect and use personal data about them without their knowledge," the letter reads.

"Therefore, it is critically important that companies like Google be completely transparent with consumers, and provide full disclosure of all technical specifications of their products at the point of sale."

It added that Google's failure to disclose the microphone's existence "raises serious questions about its commitment to consumer transparency and disclosure".

Google has said that the microphone was "never intended as a secret" and it was an error that it was not listed on the technical specifications.

But the three senators have asked for more information, including:

• details about exactly when and how Google became aware that a microphone was not listed on the technical specifications available to consumers

• whether it had always been a component

• what Google was doing to inform customers

• Google's process for developing technical specifications

• whether Google was aware of its being used by any third party for unauthorised purposes

• whether there were any similar omissions in other Google products

The letter was signed by:

• Roger Wicker, who chairs the committee on commerce, science and transportation

• John Thune, who chairs the subcommittee on technology, innovation and the internet

• Jerry Moran, who chairs the subcommittee on manufacturing, trade and consumer protection

The product in question is Nest Guard, one of Google's Nest Secure range of home security products.

The alarm and motion sensor will now be compatible with Google Assistant.

The senators have asked Google for a written response by 12 March.