Apple will stop storing voice recordings captured by Siri-enabled devices except in cases when users intentionally opt in to the practice. "[B]y default, we will no longer retain audio recordings of Siri interactions," Apple said in an announcement yesterday. "We will continue to use computer-generated transcripts to help Siri improve."
The change won't take effect right away. The default storage of Siri recordings will stop "with a future software release in fall 2019," Apple said in a support document.
Historically, Apple stored Siri recordings by default and had humans review "less than 0.2 percent" of the audio samples "to measure how well Siri was responding and to improve its reliability," Apple said.