Soundgen : a Web services based sound generation system for the psychoacoustics laboratory

Abstract

Soundgen is a web services based sound generation system developed for the MIT Psychoacoustics Laboratory Course 6.I82. The sounds created by Soundgen are combinations of various tones and noises, produced by a dedicated server running Linux, MATLAB, Apache, and PHP. As an example, Soundgen can generate a sound containing two tones of 500ms duration, each with its own frequency and phase, and can produce them over a broadband background noise. The characteristics of the tones and noises are passed to the Soundgen web service via aJSON object sent over HTTP. When the generation is complete, the web service replies with another JSON object containing the URL of the generated sound .wav file, along with some related information. Accompanying the Soundgen web service is a smallJavaScript library, easing the web service's use inJavaScript. This library allows JavaScript programmers to simply call a soundgen() function, which triggers a callback function that executes when the request has been processed by Soundgen. The library and web service allow Psychoacoustics Laboratory students to quickly and easily create portable acoustics experiments as web-applications, which can be written and run on any computer with speakers and a modern web browser.