No sound? Glitches and noise? Audio coming out of the wrong speakers? Resolving your OS X audio problems can be a time consuming process. It could be a matter of changing a simple setting or it could end up consuming most of your afternoon.
Fortunately we’ve come up with a list of everything we can think of that you can do to resolve any sound problems your Mac may encounter. Let’s begin.
First: Volume & Headphones
Before you spend all day resolving a non-existent issue, check that you have one at all. Adjust your volume (make sure it’s not muted) and check your device’s audio out port doesn’t have any earphones or other external devices plugged in.
You can’t play music from your internal speakers while another output device is connected in this port.
Check Your Sound Settings
Head to System Preferences > Sound > Output (you can search for it using Spotlight too) and check your sound settings for discrepancies. If you’re using a laptop, you’ll probably want to choose “Internal Speakers” (or “Headphones” if you’re using them). You may also see “Digital Output” if you’re not on a laptop. Make sure the desired output is selected.
Note: You can also quickly change audio input and output devices by holding the option key and clicking the speaker icon in the menu bar at the top of the screen.
Some users have reported their issues being resolved simply by switching from one output to another. You can also try plugging in headphones (or another 3.5mm jack) and pulling them out again.
Reset Core Audio & Restart
Core Audio is Apple’s low-level API for dealing with sound on the Mac. Sometimes things go wrong, and this results in no audio, and sometimes even distorted, tinny or noisy sound too. Before you restart your computer, try restarting the Core Audio process.
Open a Terminal window and input:
sudo killall coreaudiod
Hit return, input your administrator password and check whether your sound issue is resolved.
Note: You can also open Activity Monitor and search for the coreaudiod process and manually kill it.
If your issue still isn’t resolved at this stage, you should try a full restart.
Reset PRAM & SMC
There are many reasons you might want to reset your Mac’s parameter RAM (PRAM) and system management controller (SMC), and they all involve your computer doing weird things. PRAM in particular remembers certain settings related to volume and sound, so resetting that may help smooth things out.
To reset your PRAM:
- Shut down the computer.
- Press the power button.
- Before the grey screen appears, press the Command, Option, P, and R keys at the same time.
- Hold the keys until your computer restarts and you hear the startup sound a second time.
- Release the keys.
You may notice that your computer is a little slower to start up, and that certain settings have been reset (the time, volume, keyboard preferences and so on). You might also find that your sound issues have been resolved.
Realistically, resetting the SMC is unlikely to affect your sound issue but at this stage we’re guessing you’ll try the lot. The instructions for this are similarly simple, but slightly different depending on the computer you have — so check out our full article for instructions relevant to you.
Problems with External Devices
Sometimes when you connect an external device (like an HDMI TV) the sound will continue to come out of your internal speakers. To resolve this, connect the device and head back to the System Preferences > Sound menu and make sure your HDMI (or other connected device) output is selected on the Output tab.
You can also choose to output AirPlay audio to nearby devices via this interface, which is particularly handy for sharing audio separately to video.
Third Party Software Problems
You may run into an issue where your sound works in all but one app, in which case you’ll probably have to define your desired output device in that app’s settings. This is most often an issue associated with audio and video editors, like Audacity and Adobe Audition.
Instructions for each app will differ, but you’ll want to ensure you choose the same output device that appears in your Mac’s System Preferences > Sound > Output option panel. Some software may require you to create an aggregate device, which allows you to use multiple audio interfaces at the same time.
Update Your Old OS
Mavericks had a lot of sound problems, many of which cleared up with the release of Yosemite. Distorted, crackling audio and random periods of complete silence were not uncommon (killing Core Audio usually resolved it). You should update to OS X Yosemite if you’re still having Mavericks-era sound problems, particularly as 10.11 El Capitan is just around the corner.
Before you upgrade your OS make sure you’ve backed everything up, then head to the App Store and on the Updates tab you’ll see an option to upgrade to the latest version. The download may take some time, and once finished installation is straightforward.
You can even save the installer to make it easier to update other computers in your household without having to download it again.
Microphone and Input Devices
Just like output devices, input devices like audio interfaces and microphones can also be mis-configured. Head to the System Preferences > Sound > Output menu to define your output device. This particularly handy if you have connected a microphone and want to make sure you’re not using your computer’s internal one instead.
USB microphones and interfaces will appear here, alongside microphones connected via your audio port.
Can’t See “Internal Speakers” or Other Outputs?
This is a rare but fairly well-documented problem as asked on message boards and in blog comments with little in the way of a fix. It seems most common after performing an operating system upgrade, in particular the leap from 10.09 (Mavericks) to 10.10 (Yosemite).
First try installing any updates available to you. If you still encounter no devices in your Mac’s Sound preferences, you should probably back everything up with Time Machine and restore your Mac to factory settings, then restore from the backup you made.