Intermittent audio from LG monitor on Mac after macOS Golden Gate update

Intermittent audio from LG monitor on Mac after macOS Golden Gate update

This sounds like a possible macOS audio-handling issue, particularly since it started after the update and reconnecting the USB-C cable restores the sound. 

However, the cause could also involve the monitor's firmware, the USB-C connection, or how macOS recognizes the monitor's audio device.

Here are a few things worth trying before having to unplug the cable each time.

1. Re-select the LG monitor as the audio output

Go to Apple menu > System Settings > Sound > Output and select your LG monitor.

Apple's official guide explains how to select and configure audio output devices:

Change the sound output settings on Mac – Apple Support (UK)

If the monitor is missing from the list when the problem occurs, that may indicate that macOS has temporarily lost recognition of its audio device. If it remains selected but produces no sound, the issue may be with the audio connection or audio service.

2. Restart the macOS audio service

If the LG monitor remains selected but there is no sound, open Terminal and run: sudo killall coreaudiod

Enter your Mac password if prompted. The audio service should restart automatically. Then test the monitor again.

This is a troubleshooting workaround rather than an Apple-confirmed fix for this particular issue.

3. Check Apple's external-audio troubleshooting guidance

Apple's support article on sound problems explains how to check output selection, volume, mute settings, and external audio devices:

If you can’t hear sound from your Mac speakers - Apple Support (CA)

Although the article primarily addresses Mac speaker problems, its guidance on selecting audio output and checking external devices is also relevant here.

Apple also has a specific article about Macs switching audio devices while connected to external displays:

If your Mac switches to a different audio device - Apple Support (CA)

Check whether your Mac is switching away from the LG monitor or reverting to another audio device.

4. Check the USB-C cable and connection

Try another USB-C cable that supports video and audio, if available. Connect the monitor directly to the Mac rather than through a dock or hub, and test another compatible port.

Apple's external-display troubleshooting guidance recommends checking cable connections and connecting a display directly to the Mac when a dock or hub is involved:

If your external display is dark or low resolution - Apple Support

While this article focuses on display problems rather than audio specifically, checking the connection is still a useful diagnostic step.

5. Check for additional macOS updates

Since the problem began after upgrading macOS, go to System Settings > General > Software Update and check whether another update is available.

Apple's instructions are here:

How to download and install macOS - Apple Support (CA)

An additional update may resolve a software-related issue, although there is no guarantee that it will address this particular problem.

6. Check the LG monitor's firmware

Visit LG's official support website and search for your exact monitor model to check for firmware updates or known compatibility issues:

https://www.lg.com/ca_en/support/

A useful question for diagnosing the problem

When the sound disappears, does the LG monitor still appear under System Settings > Sound > Output, or does it disappear from the list entirely?

That distinction can help determine whether macOS is losing the audio device or whether the device remains recognized but stops producing sound.

Thanks for the update. Sorry to hear that the issue is still happening.

The additional detail about the delay when switching audio output back to the Mac is interesting. 

It suggests that the problem may involve macOS's audio handling rather than just the LG monitor or USB-C connection, although it is difficult to confirm the exact cause without further testing.

Since the usual troubleshooting steps have not helped, I think it is ’worth reporting this to Apple through the  Product Feedback - and make it known to Apple regarding this ongoing issue, especially if the issue started immediately after the OS update. Including your Mac model, LG monitor model, macOS version, and the audio delay you are ‘experiencing could help Apple investigate whether this is a broader software bug.

In the meantime, if you have not already tested it, you could also check whether the problem occurs in a new macOS user account. 

This may help determine whether the issue is specific to your user configuration or affects the system more generally.

Hopefully, Apple can identify the cause and address it in a future update.

Thanks. I followed the steps, but unfortunately, the issue remains. :(

I believe there's a bug in the new OS, and it's disappointing that Apple still hasn't released a fix for it.

Even just switching the audio output device back to the computer causes a delay, which never happened before.

In other words, the whole audio system seems to be strange!

fabiosilvanet wrote:

Thanks. I followed the steps, but unfortunately, the issue remains. :(

I believe there's a bug in the new OS, and it's disappointing that Apple still hasn't released a fix for it.

Even just switching the audio output device back to the computer causes a delay, which never happened before.

In other words, the whole audio system seems to be strange!

I have an LG 5K:2K Thunderbolt 3 display, connected via a Stone Pro Thunderbolt dock. I routinely switch between AirPods and the LG display for sound output, and have not had any issues with that on my 16" M4 Pro MBP running Golden Gate (upgraded on release day for 27.0, and updated to 27.0.1 and now 27.2).

BTW,

Several users are reporting the same problem on Reddit.

It's very strange that this is only happening to me :( I updated my system today, hoping the issue would finally be fixed, but unfortunately, there's still no solution. I'm disappointed.