Hacker News Reader

Comment by LeifCarrotson | Hacker News Reader

> “With a camera, you can turn it off or even put your hand over it, and no matter what you do, no one can see you,” says Fawaz. “I don’t think that exists for microphones.”

Maybe it doesn't exist on whatever sleek glassy slabs they're working with, but the old Thinkpad, Elitebook, and Precision workstation laptops I have around me at the moment all have dedicated microphone mute buttons (the Precision has a Fn key combo, the others have physical buttons that do nothing but mute the microphone) that I reach for before trying to mouse over to a different mute button for a particular videoconferencing app.

View on HN

On my Thinkpad, this was still just interpreted as an OS-level keyboard shortcut, as far as I remember.

A solution that actually (logically if not physically) deactivates any built-in microphone would arguably be at least as important as a "webcam shield".

Apple does this for the built-in microphone for their newer laptops, but that benefit is immediately negated when e.g. connecting a USB webcam that also contains a microphone.

Yes those mute lights have been stuck on "lit" (= "mute") on my Windows forever, both the mic and speaker lights. However recording and playback work fine, the lights just stay on. Very annoying, a little unsettling.

My daily driver is Ubuntu where both lights work fine, on the same machine (dual boot). But now I know not to trust them.

Lenovo ThinkPad P51

Check out if you can disable the mic in Audio MIDI Setup on Mac OS X. I tend to use the built in webcam so I’ve never looked on an external one, but in theory you should be able to selectively disable the input/output of any device via its interface. I do this to disable the mic on Work equipment and use my own AirPods as the mic input.

On my T480s the mic mute button is handled in hardware/low-level firmware however all it does is set the mic input level to 0%, where the OS can trivially set it back to 100% if it wants.

At least the LED on the button is driven by firmware based on that level, so it lights up only when the mic level is actually at 0%. While it won't prevent the OS from raising the volume, at least you'll know about it as the mute light will go off.

I generally hate my HP laptops' hardware, but this is one of the features that I really love and wish more computers had.

On the one I'm typing this on, the key actually sends a standard Media Mute signal, that can be used under Linux (complete with the LED coming on when it's muted). Ironically, this needs special drivers under Windows.

I'm going to guess the hardware switches and key combos went away because they are too confusing for users. I remember constant complaints of "Internet doesn't work" because the wifi hardware switch was turned off. And as the saying goes, if the majority of users are using it wrong, it was designed wrong.

I think Apple picked the right middle ground by making access to the mic and camera a permissions request as well as showing a clear indicator to the user whenever these are active. Steve jobs said the best UI is to ask the user for their data when you want it and keep making them aware of this access every time you use it.

The problem with software-controlled permissions is that nation-state actors (who have unbounded resources) can snoop on your private matters with significantly greater ease.

At least with a hardware switch, someone would have to physically intercept the air waves in the room you're in. In software, the surface for OS-level vulnerabilities is massive, and state sponsored mass surveillance just gets easier.

Sadly, this is a trade-off we have made as a society for "ergonomics".

This line of argument is bikeshedding at it's finest.

If Mossad is out to get you, they are going to get you, no matter what you do. The threat model for 99.999% of the population doesn't include bespoke attacks from three letter agencies.

Do these mute buttons actually hardware-mute the mic or do they send a keycode to the OS?

Usually the second. If you have multiple buttons to do it (for example dedicated button + Fn+F4 combination) then it's almost certainly software.

They seem to do both, at least on some models? On my thinkpad running openbsd, the speaker mute can become desynced. Audio won't play unless both are unmuted. Pushing the button will flip flop the software state, but not the reverse (although I believe that code could be written, it doesn't exist). So if you soft mute, then push button, hardware mutes and software unmutes, but sound still doesn't play.

I always use the key mute button on the Thinkpad, but anyway it can be muted in the system menu easily (at least in XFCE).

(In fact, I just checked in Gnome, the menu does not expose microphone volume, it's only available from the settings window.)

Reply on news.ycombinator.com