Right-click any source in the OBS Audio Mixer, open Advanced Audio Properties, and you will see an “Audio Monitoring” column with three options: Monitor Off, Monitor Only, and Monitor and Output. Pick the wrong one and you either hear nothing, hear a distracting echo, or accidentally leave a source out of your stream. Here is what each mode does and when to use it.
The three monitoring modes
Monitoring decides whether you, the streamer, hear a source in your own headphones, separately from whether your viewers hear it. This split is the part that confuses people: “Output” is for viewers, “Monitor” is for you.
| Mode | You hear it? | Viewers hear it? |
|---|---|---|
| Monitor Off | No (via OBS) | Yes |
| Monitor Only | Yes | No |
| Monitor and Output | Yes | Yes |
When to use each
Monitor Off is the default for most sources, including your game and desktop audio, because you already hear those directly from the system; letting OBS also play them back would create a doubled, echoey sound. Monitor Only suits things you want to hear but not broadcast, such as a private cue or a producer talkback. Monitor and Output is for audio that comes only through OBS and that you also need to hear, like a soundboard, a media source, or a remote guest.
Setting the monitoring device
Before monitoring works, choose where it plays. Go to Settings, Audio, and set “Monitoring Device” to your headphones. If it is set to the same output you already listen to system sound on, you can get feedback loops, so double-check it points to the correct headset. Get this wrong and Monitor Only or Monitor and Output will seem broken.
Avoiding the echo trap
The classic mistake is setting your game or desktop audio to Monitor and Output. You then hear it once from the system and again from OBS, slightly out of sync, producing an echo. Keep already-audible sources on Monitor Off and reserve monitoring for OBS-only audio.
Monitoring for soundboards and guests
The clearest way to internalise the modes is to think about where each sound originates. Game and desktop audio already reach your ears through the system, so they belong on Monitor Off; OBS still sends them to viewers. A media source or soundboard clip, however, plays only inside OBS, so if you want to hear it as you trigger it, it needs Monitor and Output. Otherwise you would fire a sound effect and have no idea whether it played.
Remote guests are the other classic case. A guest coming in through a browser source or a VoIP capture exists only within OBS, so Monitor and Output lets you converse naturally while viewers also hear them. Just make sure your monitoring device is your headphones, not your speakers, or the guest’s audio can leak back into your microphone and create an echo for everyone on the stream.
Frequently asked questions
Why can I hear an echo after changing monitoring settings?
Almost always because a source you already hear from your system, such as desktop or game audio, is set to Monitor and Output. OBS replays it a fraction of a second later, creating the echo. Set those sources back to Monitor Off and keep monitoring only for OBS-exclusive audio like soundboards or guests.
If I set a source to Monitor Only, will my stream lose that audio?
Yes. Monitor Only sends the sound to your headphones but not to viewers. Use it only for audio you deliberately want private. If a soundboard or guest must reach the stream and your ears, choose Monitor and Output instead.
Bottom line
Remember the split: Output is for viewers, Monitor is for you. Leave already-audible sources like game and desktop on Monitor Off, use Monitor Only for private cues, and use Monitor and Output for OBS-only audio you must also hear. Confirm your monitoring device points to your headphones, and the echoes disappear.
