Mozilla is working on giving Firefox users a feature to see which open browser tabs are playing audio and, if they choose, mute those noisy tabs. This feature, which exists in similar fashion for Google's Chrome and Apple's Safari browsers, would fulfill a request made in March 2009.

"Mozilla is currently working on adding a feature for Firefox to display an icon in tabs that play sound, and additionally allows users to mute such tabs," said Ehsan Akhgari, Web API tech lead at Mozilla, in an interview with VentureBeat. "The feature has not been released yet, but it is expected to work similarly for Flash content on Windows and Mac, which is where the new Flash API is supported."

Akhgari added that the audio indicator and mute feature is currently in review and that Mozilla doesn't have an estimated timeline for the feature's official arrival to Firefox.

The feature request was made in Bug 486262 on March 31, 2009, with this expected result: "Provide visual indication in tab title that this website is causing sound, so it can be quickly muted or attended to."

While this functionality has been available for Firefox users via browser add-ons and extensions, demand for it to be built into the browser has persisted. Chrome has audio icons on tabs playing sound but doesn't allow users to mute those tabs by default. Safari has audio indicators and gives users the option to mute tabs.