Human workers can listen to Google Assistant records.

SAN FRANCISCO >> Google's subcontractors regularly listen and review some recordings of what people are saying about the Google Assistant Artificial Intelligence System, via their phone or smart speakers like Google Home.

The company has acknowledged that humans can access these recordings after the leak of some audio extracts in Dutch. Google product manager David Monsees acknowledged the leak in a blog on Thursday and said the company was investigating the breach.

"We are in the process of conducting a comprehensive review of our safeguards in this space to prevent such reprehensible behavior from happening again," he wrote.

The Belgian broadcaster VRT NWS obtained more than 1,000 recordings and noted in a story that some contained sensitive personal conversations – as well as information to identify who was speaking. Google says that no user account information is associated with records, and reviewers are advised not to transcribe conversations in the background.

But VRT journalists could hear spoken addresses at home in some recordings and were able to locate the speakers. Some of these conversations were not directed at the assistant and occurred either as a background noise or as an erroneous recording while the assistant thought he was being talked about, but was not.

Google indicates that subcontractors listen to recordings to better understand language patterns and accents. Its terms of use confirm that the recordings can be used by the company, stating that Assistant "records your voice and audio data on Google services to improve speech recognition."

Monsees wrote that Google collaborates with subcontractors around the world to analyze records.

"These language experts are studying and transcribing a small set of questions to help us better understand these languages," he wrote.

Google's terms do not explicitly state that people review the records, but specify that the data can be analyzed when the company updates the services or creates new features.

The company acknowledged earlier this year that its critics were listening to anonymous recordings in response to a Bloomberg report revealing that Amazon's Amazon also used subcontractors to listen to the recordings. Amazon has confirmed the report.

Google's registration feature may be disabled, but this means that the wizard loses part of its custom key. People who disable the recording function lose the ability for the assistant to recognize individual voices and learn your voice pattern.

The wizard registration is disabled by default, but the technology prompts users to enable registration and other tools to get custom features.

Google Assistant is available on more than one billion devices, including smartphones and smart speakers. The smart speaker market, which is still the main place where people use voice technology, has yet to get noticed, but it still remains behind Amazon.