SoundManager 2 : Using HTML5 and Flash, SoundManager 2 provides reliable cross-platform audio under a single JavaScript API.
jsmad : jsmad is a pure javascript MP3 decoder, based on libmad, with an ID3 decoder written from scratch.
meSpeak.js : meSpeak.js (modulary enhanced speak.js) is a 100% client-side JavaScript text-to-speech library
Band.js : An interface for the Web Audio API that supports rhythms, multiple instruments, repeating sections, and complex time signatures.
dancer.js : dancer.js is a high-level audio API, usable with both Mozilla's Audio Data API and Webkit's Web Audio API with flash fallback, designed to make sweet ...
howler.js is an audio library for the modern web. It defaults to Web Audio API and falls back to HTML5 Audio. This makes working with audio in JavaScript easy and reliable across all platforms.