[ddagradi]

He even gets basic facts incorrect. The author assumes his Macbook Pro doesn't have a dedicated audio input. It does. Every Macbook Pro does. (The Macbook Air is the only Mac shipping without a built-in audio input).

Really, what I see is a software update that fixes a user interface bug. System Preferences no longer offers disconnected audio inputs as a selectable option, because it's just plain smarter that way. Could there any possible confusion for an average user between "Internal Microphone - Built In" and "Line In - Audio Line In" when looking at their sound input options? Seems like a design decision made in the interest of removing irrelevant choices.

[mickael1]

The 13 inch Macbook Pro, just like the Air, does not have a dedicated audio input. It's one of those mobile phone headphone/microphone combo jacks.

[bbloomberg]

Hold down option and click the volume icon in the menu bar, select "Use Audio Port for: Input"

[DanBC]

The ability to switch between input and output suggests it's not a dedicated input port.

[ddagradi]

The Macbook Air does not have a combo port (currently). Just a headphone jack. I used dedicated to mean "includes specific hardware to handle this use case". Sorry for the ambiguity.

The consumer product line continues to have fewer fine-grained controls than Pro products, so nothing has really changed here.

[r00fus]

Not sure if you're correct - look at the specs page [1]... it does support the Apple headset with combo microphone/headphones port.

[1] http://www.apple.com/macbookair/specs.html

[ddagradi]

Interesting! The language on the MBP specs says "Combined headphone/line in", whereas the MBA specs say "Headphone port". But you are correct: my headphones register as an audio input on the Macbook Air. I wonder if it's a very specific exception, or just an intentionially undisclosed feature (why?).

[mikeash]

I would read "combined headphone/line in" as meaning that it would do full stereo line-level audio if you provided it. The MBA's port only works with four-pin cell phone-style headsets, as far as I know, which do mono over an extra pin while still providing stereo output.

[dedward]

so despiteall that, when you are using the prefs screen and turn the input volume theway cown, it should not register any input right? Thenwhy does it? thas not nothing.

[moheeb]

A microphone is a mechanical device, so it will always produce output regardless of what your volume settings may be.

To get technical, you are controlling the gain of the volume of the stage after the microphone. So in the real world the microphone should always show input unless physically disconnected. Computer manufacturers don't follow any standard practices it seems, so you may see it both ways.

[ddagradi]

Sounds like a bug. I can't reproduce it on my Air, and it appears other commenters have difficulty reproducing it as well. The OP/commenters experiencing the issue should probably file a Radar.