Apple released documentation today on their T2 chip, included with the new Macs released today, as well as the MacBook Pros released earlier this year. The T2 security chip helps to protect encryption keys, encrypted storage, fingerprint data, and secure boot features.
But a vital feature that was unknown until today is that it also provides hardware-level protection of the device’s microphone. When the lid is closed on the new laptops, the internal microphone is disconnected at the hardware level. This means it is impossible for a hacker to eavesdrop on your audio as long as the lid is closed. To the best of my knowledge, no other computer offers this level of audio security.
Of note is that the T2 does not cut off the internal webcam when the lid is closed, because, well, the lid is closed!