New York (CNN Business) It appears no one realized Google's Nest Guard home security device has a built-in microphone.

Google Assistant would roll out to Nest Guard so users can ask it for information like the weather or traffic. The blog post acknowledged the gadget has one microphone -- news that was not made clear to users. In a blog post earlier this month, the company announcedGoogle Assistant would roll out to Nest Guard so users can ask it for information like the weather or traffic. The blog post acknowledged the gadget has one microphone -- news that was not made clear to users.

Google previously did not disclose the microphone's existence in any of its product descriptions but said it wasn't a "secret."

"The on-device microphone was never intended to be a secret and should have been listed in the tech specs. That was an error on our part," a Google spokesperson told CNN Business on Wednesday in a statement.

The microphone isn't enabled by default and can only be activated when users turn on the option. A Google spokesperson said it included the microphone on the device so it could potentially offer users additional features, such as the ability to detect broken glass during a break in.

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