What’s that song? On your cellphone, the popular app Shazam is able to answer that question by listening for just a few seconds, as if it were magic. On Apple’s computers, Shazam never turns the microphone off, even if you tell it to.
When a user of Shazam’s Mac app turns the app “OFF,” the app actually keeps the microphone on in the background. For the security researcher who discovered that the mic is always on, it's a bug that users should know about. For Shazam, it’s just a feature that makes the app work better.
https://motherboard.vice.com/read/shazam-ke...you-turn-it-off