In simple words: Without the Web Audio API Support, audio on the web required a plugin – Firefox users unlike Chrome users needed to have Flash, QuickTime or another plugin to break the silence of the web.
Intro of the Web Audio API specification:
“The introduction of the audio element in HTML5 is very important, allowing for basic streaming audio playback. But, it is not powerful enough to handle more complex audio applications. For sophisticated web-based games or interactive applications, another solution is required. It is a goal of this specification to include the capabilities found in modern game audio engines as well as some of the mixing, processing, and filtering tasks that are found in modern desktop audio production applications”
The Web Audio API specification includes a set of example applications, including multi-player games like Quake, musical examples and more.
Cutting-edge Firefox web browser users and fans can download Firefox 23 Aurora or Firefox 24 Nightly and get a firsthand test.