Google is investigating how 1,000 conversations recorded by one of its smart speakers were leaked.
Belgian broadcaster VRT exposed the recordings made by Google Home devices in Belgium and the Netherlands.
The search giant said the recordings came from one of the human reviewers who helps to refine Home's linguistic abilities.
It said it took steps to protect the privacy of people whose recordings its reviewers sampled.
VRT said the majority of the recordings it reviewed were short clips logged by the Google Home devices as owners used them.
However, it said, 153 were "conversations that should never have been recorded" because the wake phrase of "OK Google" was not given.
These unintentionally recorded exchanges included:
- blazing rows
- bedroom chatter
- parents talking to their children
- phone calls exposing confidential information
It said it believed the devices logged these conversations because users said a word or phrase that sounded similar to "OK Google" that triggered the device.
Responding in its blog to the VRT expose, Google said it shared recordings with experts who "understand the nuances and accents" of specific languages to make its speaker more accurate.
"This is a critical part of the process of building speech technology," it said, adding that the storing of recordings is turned off by default when people start using its Home devices.
It added that it was probing how one of its contractors had been able to give VRT access to the database of recorded chatter.
"Our security and privacy response teams have been activated on this issue, are investigating, and we will take action," it wrote.