Wave.js : Audio visualizer library for javascript. Create dynamic animations that react to an audio file or audio stream.
D3.js : D3.js is a JavaScript library for manipulating documents based on data. D3 helps you bring data to life using HTML, SVG and CSS. D3’s emphasis on web ...
jsfx : This is a javascript library (with frontend) for sound effect generation.
jsmad : jsmad is a pure javascript MP3 decoder, based on libmad, with an ID3 decoder written from scratch.
howler.js : howler.js is an audio library for the modern web. It defaults to Web Audio API and falls back to HTML5 Audio.
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 visualizations.