Music starts somewhere among a dozen open tabs. Turning the computer’s volume down stops the interruption, but it also silences the call you actually want to hear. First try to identify which tab is producing the sound.
Look along the tab strip for an audio indicator. In Firefox, Mozilla’s tab-audio guidance explains that the speaker button identifies a noisy tab and can mute or unmute that tab individually. Other browsers may expose different controls, including settings that apply to a whole site.
Use the narrowest control that solves the interruption
Mute the suspected tab, then listen. If the unwanted audio stops while the call continues, you have isolated the source without changing the whole computer’s output. If it continues, check other browser windows and running applications before repeatedly changing unrelated settings.
Open the responsible page when convenient and inspect its player. Muting audio and pausing playback are separate actions. If you no longer need the video or stream, pause it or close the page rather than assuming a silent tab has stopped doing anything.
Remember the quiet tab later
A muted tab can become tomorrow’s troubleshooting puzzle. Before changing headphones or reinstalling anything because a particular page is silent, check its player volume and tab or site mute state. Then check the application’s output and the computer’s selected audio device.
During a meeting, make one change at a time. An invented example: mute a news tab, confirm the speaker remains audible, then return to the meeting. That gives you a clear result to reverse if needed.
Be careful with microphone controls: silencing what you hear does not establish whether other people can hear you. Check the meeting application’s microphone indicator separately when you need to stop transmitting your voice.
A little isolation is usually more informative than turning every sound control down and later wondering which one to restore.