Apple has apologised following revelations that it paid third-party workers to listen to voice recordings of Siri users.
The practice known as "grading" has been used by several tech firms as a way of improving the quality of speech recognition.
However, Apple, Google and Microsoft all halted such work recently, following public outcry.
Apple said it plans to resume grading - but only for Siri users who opt in.
The firm added that in the future only its own employees will be able to access recordings, not third-party workers at contracted firms.
Earlier this month, the company said it had halted grading following reports that workers had heard recordings containing intimate remarks made by Siri users.
Such recordings can be made accidentally, for example when the Siri app interprets another word or noise as the utterance "Hey Siri", which is used to launch voice recognition.
Now, Apple says it has completed a review of such work.
"As a result of our review, we realise we haven't been fully living up to our high ideals, and for that we apologise," the firm said in a statement.
It added that three main changes would take place before human grading of Siri recordings was resumed. It said:
- audio recordings will no longer be retained by default. Instead, Apple employees will rely on computer-generated transcripts of speech
- Siri users will be able to opt in to share audio recordings and they will also be able to opt out "at any time"
- only Apple employees will have access to recordings and recordings which have been made "inadvertently" will be deleted
A spokeswoman for Ireland's data protection commission, Apple's lead data privacy regulator in Europe, said the commission had noted the company's new statement on the matter of grading.
More to follow...