Where apps hide your files

Alert sounds and system sounds, folder by folder

Updated 2026-10-28 · 6 min read

The Mac's built-in alert sounds are in a locked system folder, and the one you can add to is in your Library. One catch: System Settings shows them under different names from the files. This covers both folders, the name map, and where the other tones hide.

Where the sounds live

The built-in alert sounds are 14 AIFF files here:

/System/Library/Sounds/

Your own alert sounds go here, in your home folder:

~/Library/Sounds/

If ~/Library/Sounds does not exist, create it:

mkdir -p ~/Library/Sounds

The first folder belongs to macOS and cannot be changed. The second belongs to you and is the place for custom alert sounds.

The names in Settings are not the file names

On recent macOS (checked on Sequoia 15.6), System Settings > Sound > Alert sound lists the built-in sounds under newer display names, while the files keep their classic names. The mapping comes from the Sound settings' own name table:

Name in Settings	File in /System/Library/Sounds
Boop	Tink.aiff
Breeze	Blow.aiff
Bubble	Pop.aiff
Crystal	Glass.aiff
Funky	Funk.aiff
Heroine	Hero.aiff
Jump	Frog.aiff
Mezzo	Basso.aiff
Pebble	Bottle.aiff
Pluck	Purr.aiff
Pong	Morse.aiff
Sonar	Ping.aiff
Sonumi	Sosumi.aiff
Submerge	Submarine.aiff

So if you want a copy of the sound Settings calls Crystal, the file is Glass.aiff. Older macOS versions show the file names directly.

Open the folders

• Finder: Go > Go to Folder (⇧⌘G), paste /System/Library/Sounds and press Return.
• Terminal: open /System/Library/Sounds
• For your own folder: open ~/Library/Sounds. In Finder, hold ⌥ while the Go menu is open and Library appears in it.

Select a sound in Finder and press Space to hear it in Quick Look. From Terminal: afplay /System/Library/Sounds/Glass.aiff.

Adding a custom alert sound

1. Get your sound as an AIFF file, the format Apple's own alert sounds use.
2. Copy it into ~/Library/Sounds/.
3. Open System Settings > Sound. In the Sound Effects section, open the Alert sound menu; your file should be listed by its name, without the extension. If it is missing, quit and reopen System Settings, and as a last resort log out and back in.
4. Choose it. It becomes the beep macOS plays for alerts and for apps that use the standard system alert.

If your clip is a WAV or MP3, convert it with the afconvert tool built into macOS. This writes a new AIFF and leaves the original alone:

afconvert -f AIFF -d BEI16 ~/Downloads/ding.wav ~/Library/Sounds/ding.aiff

Keep alert sounds short, a second or two. A long clip is annoying every time an app beeps.

Why you cannot edit the system folder

/System is on the read-only system volume that macOS has used since Catalina, and since Big Sur that volume is also cryptographically sealed. You cannot add to, rename or replace anything in /System/Library/Sounds, even with an administrator password, and a system update would restore the originals anyway. Copy a built-in sound into ~/Library/Sounds/ under a new name and change the copy.

Other sound folders you may be looking for

The alert sounds are not the only audio macOS ships:

What	Where
Interface sounds (Dock, Finder, FaceTime, Siri and more)	/System/Library/Components/CoreAudio.component/Contents/SharedSupport/SystemSounds/, in folders such as dock, finder, facetime, siri, system, telephony
Notification and message tones	/System/Library/PrivateFrameworks/ToneLibrary.framework/Versions/A/Resources/AlertTones/, in sets named Classic, Modern and EncoreInfinitum

Both are system-owned and read-only, same as the alert folder. They are useful for finding a name or copying a file out to reuse, not for swapping sounds in place. The tones in Classic and Modern are .m4r files (the iPhone ringtone format) and the newer set is .caf; the exact contents change between macOS releases.

Space and cleanup

Sound files are tiny, so there is nothing to reclaim in the system folders. In your own folder, drag a custom sound you no longer use to the Trash. If Sound settings still lists it, quit System Settings and reopen it.

Do not try to delete anything under /System. macOS will not let you, and it needs those files.

Backing up and moving to a new Mac

Only ~/Library/Sounds needs saving, because the built-in sounds come with every copy of macOS. Copy the folder to the new Mac's ~/Library/Sounds, or let Migration Assistant move it with the rest of your account. Time Machine includes it too. The choice of alert sound is a separate setting, so pick it again under Alert sound if it did not carry over.

Why Spotlight never shows these

Spotlight does not return results from ~/Library or from inside /System, so searching for "Glass" or your own ding.aiff gives you nothing, and searching for "Crystal" would not match a file anyway.

Finding a sound by name next time

Type a file name, say Submarine or .aiff, into Everywhere and the built-in copy in /System/Library/Sounds and anything in your own ~/Library/Sounds show up together, along with the interface sounds tucked inside the CoreAudio component. Search for the file name from the table above, not the name in Settings, and press ⌘Y to preview a file before you copy it.

Common questions

Where is the system alert sound folder on a Mac?

The built-in alert sounds are in /System/Library/Sounds, and custom ones go in ~/Library/Sounds. You choose the active one in System Settings > Sound under Alert sound.

Why can't I find the Crystal or Submerge sound file?

Recent macOS versions show the built-in alert sounds under new names in Sound settings, but the files keep their old names. Crystal is Glass.aiff and Submerge is Submarine.aiff, both in /System/Library/Sounds.

How do I add a custom alert sound on macOS?

Put an AIFF file in ~/Library/Sounds (create the folder if it is missing), then choose it under Alert sound in System Settings > Sound. Convert WAV or MP3 files first with afconvert.

Can I replace the built-in Mac sounds?

Not in place. /System is on the read-only, sealed system volume, so copy the sound to ~/Library/Sounds under a new name and edit the copy.