I'm not clear why people are poo-pooing this as if it's not a big deal. From a security and espionage point of view this is pretty significant - the audio learning has got to the point that a sensitive audio bug can bascially be key logger. There are a ton of context where an audio tap would be much easier to get in place than a traditional network attack (and with modern shotgun mics, might not even require being in…
Better yet, play some white noise around you. I heard that it's actually done sometimes at really important meetings.
If you're not such a VIP, just type important things only on your phone; touch screens don't produce enough sound, hopefully.