Q: Since I installed El Capitan I have not been able to hear audio in my headsets while recording to audio software on my Macbook  Pro.  Does anyone know how to fix this?

Are you using any type of audio interface? If so, make sure your device drivers are El Cap compatible.

Like wise check for any Adobe Audition updates. Is this the Creative Cloud version?

How is your microphone and headphones set up?

Finally look in Audio MIDI setup

Hope this helps, Greg

I'm encountering a similar phenomenon: Sound through my iMac speakers works just fine, but if I plug in headphones or an external speaker system, there is no sound and the Sound Volume icon in the menubar immediately dims.  If I go to the Sound preference pane, there is no Line Out option at all: just internal speakers.

-gf

Hi Vicon

Apple is changing many of the underlying frameworks and associated APIs for audio and video. El Capitan introduced many changes and broke lots of hardware/software for audio interfaces and software.

Most interfaces depend on "drivers" to function. Not sure about iMic. You will need to go to Apogee's website and see if new drivers exist and if they are still supporting that device. Sorry to say, my closet has many outdated, no longer supported devices. Even my current Focusrite 18i20 has had some issues and I don't think Focusrite has updated the Mix Control software yet.

Some of the older USB devices depended on using built-in Core Audio device support and with El Capitan, these got flakey to say the least.

AFIK Jack Router OS X has not been updated since 2013/14 and most likely is not compatible.

Many other free routing software also broke like SoundFlower. There is a new version of SF 2.0.2b2  that partially fixes SF and the original developer has taken over development again so a new version is in the works. Rogue Amoeba was maintaining SF for many years, but they decided to drop free apps. They have some commercial apps that may provide you a working interface. I have not use them, so try before you buy  https://rogueamoeba.com/

One app to check out by them is Loop Back

One thing to try is using GarageBand to see if it would work.

The next thing I would suggest is to create a bootable external drive (ssd is preferred) with Yosemite or Mavericks installed just for recording.

It is possible that solutions will be coming in the future, but it is already pretty late in the game of EC so I assume if the developers/manufactures were planning on updating, they would have. It is always best to make sure all of your devices and software is compatible before upgrading OS.

It is up to the developers/manufacture's to provide this support, NOT Apple.

Sorry I can't help more.

Greg

Hi Gregory

If you are just using the 3,5mm audio in plug, no external interfaces/software, it should automatically switch from internal to headphones or external speakers.

The first thing is to try different headphones, you may have a short in your current ones. It is also possible you have a bad circuit/jack in the computer itself but that requires a trip to a service center.

What shows up in System Preferences > Sound or the Menu Bar Option key icon, is contextual. This means you will only see an option if something is available. If this isn't the case, you have a corrupted file somewhere.

If you are comfortable with Terminal, there may be a fix using it. Otherwise, you may want to reinstall the OS via recovery mode. This will leave all your personal files in place and only replaces the underlying OS. You could also attempt using Disk Utility in Recovery Mode to Repair Disk.

OS X: About OS X Recovery - Apple Support

Before you do, please make sure you have back-ups. I personally keep at least 3/4 back-ups. Time Machine and Carbon Copy Cloner

Hope this helps, Greg