What Is Audio Ducking? Meaning, Uses and Mac Settings

Short answer: Audio ducking means one sound is turned down automatically while another one plays, then comes back up. Radio uses it to lower music under a presenter. On a Mac you meet it as music that drops during a call or while VoiceOver speaks.

What is audio ducking?

Wikipedia's definition is short: "In ducking, the level of one audio signal is reduced by the presence of another signal." The sound that matters, usually a voice, is the trigger. The sound in the background, usually music, is the one that gets "ducked": it dips while the voice is there and rises again when the voice stops.

You hear it every day, mostly without noticing:

• Radio and DJs: music drops when the presenter talks.
• Podcasts and voice-over: a music bed sits under the host and swells in the gaps.
• Streaming: game or music audio dips while the streamer speaks.
• Your computer and phone: media gets quieter during calls, navigation prompts or a screen reader.

How does audio ducking work?

In an editor or a broadcast mixer, ducking has a few settings. The names differ between tools, but the ideas are the same:

• Trigger signal: the sound that causes the dip, for example the voice track.
• Threshold: how loud the trigger has to be before ducking starts, so breathing or room noise does not set it off.
• Duck amount: how far the background drops, set in decibels.
• Attack: how quickly the background goes down once the trigger starts.
• Release (or hold): how long the background waits, and how slowly it comes back, after the trigger stops.

A release that is too fast makes the music pump up between sentences.

Ducking vs manual volume automation

In an editor you can also draw the music level by hand under each sentence. That gives full control; ducking does the same job automatically, and works live.

Ducking vs sidechain compression

Both lower one signal because another one is present, and many tools build ducking on top of a sidechain input. The difference, as Wikipedia puts it: "in ducking the attenuation is by a specific range while side-chain compression creates variable attenuation."

In practice:

• Ducking drops the background by a set amount whenever the trigger is there.
• Sidechain compression turns the background down more when the trigger is louder and less when it is quieter. Music producers use it for the "pumping" effect, where a kick drum pushes the rest of the track down on every beat.

For music under speech, ducking is the simpler tool.

What audio ducking looks like on a Mac

When you are just listening on a Mac, nobody sets thresholds. Ducking shows up as something that happens to you: the music gets quieter, and you did not touch a volume control. The usual sources:

• VoiceOver. Apple's VoiceOver User Guide says that "by default, the volume of audio content, such as a podcast or music, is appropriately reduced whenever VoiceOver speaks."
• FaceTime calls, by user reports. Users on Apple's community forum report that other audio gets much quieter during FaceTime calls, and that they found no setting to stop it.
• Other call apps. Zoom, Teams, Discord and other call apps process their own audio, and some have settings that adjust levels automatically.
• Bluetooth headsets. When a call uses the microphone in your AirPods or Bluetooth headphones, many switch to a headset mode that sounds quieter. It is not ducking, but it feels the same.
• Audio utilities you installed, including a per-app mixer like SoundDial (more below).

How do I turn off audio ducking on Mac?

It depends on what is doing it.

VoiceOver ducking: open VoiceOver Utility (Applications > Utilities), choose the Sound category and turn off "Enable audio ducking". Apple's guide describes this checkbox for VoiceOver only: it stops VoiceOver from lowering other audio while it speaks. In one Apple Community thread it helped the original poster but not several others.

FaceTime: users in a second Apple Community thread found no setting for it. What you can control is the rest of the mix, below.

Call apps: open the app's audio settings and look for options that adjust volume automatically. In Discord, the setting is called Attenuation, under Voice & Video.

Bluetooth headset mode: choose a different microphone in the call app, for example the Mac's built-in one, so your headphones stay in their normal playback mode.

SoundDial: if you use it, the setting "Lower other apps during calls" is on by default. Turn it off, or raise its level so music only dips a little.

For a cause-by-cause walkthrough, see how to disable audio ducking on Mac.

Why is my Mac audio low after a FaceTime call?

Users report this on Apple's own community forum: in a thread titled "How to disable audio ducking? Ducking not deactivating after Facetime call", a user describes other audio frequently staying lowered after a FaceTime call, on macOS Catalina and earlier, with a restart as their fix at the time. A reply suggests the VoiceOver "Enable audio ducking" checkbox; it helped the original poster but not several others.

So treat it as a user report, not a documented macOS behavior. If it happens to you:

1. Check the volume inside the app that sounds quiet; it may simply have been turned down.
2. Check System Settings > Sound > Output for the right device and level.
3. If a Bluetooth headset is connected, disconnect and reconnect it so it leaves headset mode.
4. Restart the audio service with sudo killall coreaudiod in Terminal, or restart the Mac.

If you run SoundDial, its levels come back on their own when the call ends, and Settings shows "No call right now" once it no longer sees a call.

How can I duck music automatically while on a call?

Here you are not editing, you are listening: music plays in Spotify, a call starts in Zoom, and you want the music lower while the call is on.

macOS has one output volume for every app, so lowering it lowers the call too. SoundDial does the ducking per app instead:

• Trigger: a call app or a listed browser reports that it is using audio input. SoundDial does not read or record microphone audio; it only checks whether input is in use.
• Duck amount: other playing apps play at a level you choose, from 5% to 80% of their volume in 5% steps. The default is 30%.
• The call stays loud: the calling app and other communication apps are never lowered.
• Release: when the call ends, every app returns to its own level.

The call apps are Zoom, Microsoft Teams, FaceTime, Discord, Slack, Webex, Skype, WhatsApp and Telegram, plus the system's call services. The browsers are Safari, Chrome, Chrome Beta, Firefox, Edge, Arc, Brave, Opera and Vivaldi, so a web call counts too. One limit: a listed browser using the microphone for something else, such as dictation, also triggers the dip.

While a call is detected, SoundDial's menu shows "Call – others lowered" and the lowered apps show a "Ducked" chip. The setting is "Lower other apps during calls" in SoundDial's Settings, under Auto-Duck, and you can switch it off at any time. Ducking is one part of a per-app mixer: each app also has its own slider from 0% to 200%. More on the setup: audio ducking on Mac.

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