Mac privacy feature you may not have heard of

Many people who use a new Macbook in “Clamshell mode” (lid closed, and connected to an external display) may inadvertently be familiar with this privacy feature.

This innovative feature occurs when you close your Macbook’s lid. The microphone is then disconnected at a hardware level.

It is limited to Apple devices with the T2 chip:

All 13-inch MacBook Pro and MacBook Air notebooks with the T2 chip, all MacBook notebooks with a T2 chip from 2019 or later, and Mac notebooks with Apple silicon, this disconnect is implemented in hardware alone.

What this means is that if you close your laptop and it for some reason doesn’t go to sleep, or it enters “clamshell mode” that the participants in the audio call you were in will no longer be able to hear you.

Facing issues from no microphone input#

This can be a problem for people like myself that have “docked” my Macbook with an external display, and have joined a call and been unaware of why the participants can’t hear me even allowing all software privacy measures to access the microphone.

A privacy feature that you can either love or hate is relevant to anyone using Zoom, Discord, Facetime, Teams and any other app that uses your microphone.

All you need to do to resolve an issue of not being heard, is to simply open your Macbook.

What else does the T2 chip do?#

Apple includes a circuit and very detailed information about how the T2 security chip works in Macs that have it.

The T2 chip offers other features, like an image signal processor that enables enhanced face detection-based auto exposure, controls the ambient sensor, the system management controller (SMC), Apple video encoder, audio controller, and enables siri spoken commands via “Hey Siri.”

TLDR;#

There is a security chip in new Macs that disconnects the microphone at a hardware level when you close your Macbook lid.

I’m a privacy advocate, and do believe initiatives such as this are a good step in a device where you can’t just remove the privacy flaw completely (removing a USB).

Read more#

If you want to find out more about Apple’s platform security, you can [download a PDF](The T2 chip offers some non-security features as well, like an image signal processor that enables enhanced tone mapping, controls the ambient sensor, the system management controller (SMC), white balancing to the FaceTime HD camera, Apple video encoder, audio controller, and enables “Hey Siri.") from their website.

As always, feel free to message me on twitter if you’d like to start a discussion.