Non sono sicuro di come lo faresti in modo nativo, ma per pura coincidenza l'ho scoperto oggi, da Obdev, i creatori di Little Snitch.
Micro Snitch
Ever wondered if an application records audio through your Mac’s built-in microphone without your knowledge? Or if the camera captures video for no good reason?
With Micro Snitch there’s no doubt anymore. This ultra-light menu bar application operates inconspicuously in the background. It monitors and reports any microphone and camera activity to help you figure out if someone’s spying on you.
Logging
Never miss any microphone or camera activity, even in your absence. Every status change is logged to a file, so you can review it later to find suspicious activities.
€ 3,99 diretto, o anche su Mac App Store che mostra a $ 3,99 USA o £ 2,99 Regno Unito
Nessuna affiliazione, & Non l'ho provato da solo; Sono solo un utente soddisfatto di Little Snitch.