New York (CNN Business) Apple apologized on Wednesday for letting contractors listen to commands that users give to its voice assistant Siri. The company is now promising changes.

Apple AAPL The practice, which is designed to improve the quality of Siri, came under scrutiny after The Guardian reported last month that contractors could hear users' private conversations.initially responded by temporarily suspending the practice earlier this month while the company reviewed it.

In a blog post Wednesday, Apple said it will require users to opt in to having their recordings listened to by human reviewers, rather than having this be the default. And only Apple employees will be allowed to listen to audio samples of the Siri interactions, rather than contract workers.

The company also said it will no longer keep audio recordings of users' interactions with Siri.

"We know that customers have been concerned by recent reports of people listening to audio Siri recordings as part of our Siri quality evaluation process," Apple said in the post. "As a result of our review, we realize we haven't been fully living up to our high ideals, and for that we apologize."