when i plug in earphones/headphones into my computer (macbook pro 13 ) it doesnt work and the sound comes out of the built in speakers.

This helped me THANK YOU SO MUCH, I had this problem for months, THANK YOU SO MUCH!

For my Macbook Air (mid-2013 / OS Yosemite 10.10.5), it use to happen automatically when I simply plugged in my headphones. Now I have to go into System Preferences and switch back and forth?? This doesn't make sense. Please help ...... Thanks,

Perfect! I fixed my issue using Aaplluvr's 2nd suggestion.

First I tried their suggestion to do ALT/Option + Volume icon. For my, my headphones were already selected (JABRA Headset) for both input and output, which was strange. I also found that videos etc would still go through headphones.

So then I saw the second solution which was to go to the "Audio MIDI Setup" and play with the settings there.

What I changed was Right Clicking on my "Jabra UC VOICE 550 MS USB" headset (Or for other people, select the headphones you are trying to use).

Then I clicked on "Play alerts and sound effects through this device" and then that meant all 3 options were now greyed out and activated against that device. (Sound input, output, and alerts/effects).

Problem fixed!

I have found an easier method than described below. When my MacBook Pro was new, it accepted headphones without a problem. Then after a couple of years, with no change that I know of, the sound quit coming through the same headphones. I checked this community with no luck on descriptions. However, every month or so, I "Restart" my computer, even though I disable caches on the computer... To my surprise, the headphones started producing sound again... then it has happened 2 more times, and Restart has solved the problem.

Good luck!

Nancy

This didn't work because the earpiece is not even showing ...