Mac Volume Keeps Changing by Itself: How to Fix It

You set your Mac volume to a comfortable level. You look away. When you come back, it's different: louder, quieter, or back at maximum. It keeps happening, and you can't figure out why.

It feels random, but there's almost always a specific trigger. Here are the common causes and how to fix each one.

1. A Bluetooth device connected or disconnected

This is the most common cause. macOS remembers a separate volume level for each output device. When AirPods, headphones or a speaker connect or disconnect, the volume jumps to whatever level you last used on that device. If you were at 30% on your speakers and your AirPods auto-connect, the volume can jump to the 80% you last used on the AirPods.

Fix: each time you switch, set the volume where you want it; macOS will remember it for that device. If a Bluetooth device keeps connecting unexpectedly, go to System Settings > Bluetooth and remove devices you don't use.

2. An external display took over the audio

Many displays connected over HDMI or DisplayPort are also audio outputs, and macOS can switch to them automatically. When the display sleeps or disconnects, macOS switches back to the speakers, at the speakers' volume.

Fix: check System Settings > Sound > Output and select the output you want. If you never want audio through your display, some displays let you turn off their speakers in their own on-screen menu.

3. An app is changing the volume

Some apps adjust volume on their own. Call apps can adjust audio levels automatically, and music apps with volume normalization make songs sound louder or quieter than each other.

Fix: check the audio settings of apps you opened recently. In Zoom, look in Settings > Audio for options that adjust volume automatically. In Spotify, look for a Normalize volume option in its playback settings.

4. A key press or the Touch Bar

A brushed volume key, or a stuck one, changes the volume. The Touch Bar on older MacBook Pro models is easy to touch by accident.

Fix: watch the volume indicator while you're not touching anything to spot a stuck key. On Touch Bar models, customize the Touch Bar (System Settings > Keyboard > Touch Bar Settings) to move or remove the volume control.

5. The audio service reset after sleep

After sleep, the macOS audio service (coreaudiod) sometimes restarts and comes back at a different volume.

Fix: if volume keeps resetting after wake, restart the audio service manually. Open Terminal and run:

sudo killall coreaudiod

If it keeps happening after every update, check for a newer macOS update.

6. Accessibility settings

Open System Settings > Accessibility > Audio and check for anything unexpected. Also make sure VoiceOver isn't turned on by accident.

Keep one app from drowning out the rest

Many "volume keeps changing" complaints are really about one app being suddenly too loud or too quiet compared with the others: a notification blasting after the volume jumps, music burying a call.

macOS only gives you one slider for everything. SoundDial adds a volume slider for each app in your menu bar, so you can:

• Lower one loud app without touching the others
• Mute an app that keeps making noise, like a chat app
• Boost a quiet app, such as a call, above 100%, up to 200%

It doesn't stop macOS from changing the system volume, but it lets you fix the mix between apps in a couple of clicks. One thing to know if you use it: SoundDial's auto-ducking (on by default) lowers other apps while a call app uses the microphone and restores them when the call ends. If other apps get quieter during calls, that's the reason; you can change the level or turn it off in SoundDial's settings.

SoundDial is a per-app volume mixer for Mac, €14.99 one-time purchase on the Mac App Store with no subscription, and needs macOS 14.2 or later.

Get SoundDial on the Mac App Store.