An organization for high-level interactive control of sound

Abstract

The state of computer generated sound has advanced rapidly, and there exist many different ways of conceptualizing the abstract sound structures that comprise music and other complex organizations of sound. Many of these methods are radically diierent from one another, and so are not ususally used within the same system. One problem that almost all methods share is one of control, as large amounts of data are needed to specify sounds. How do we create, examine, and modify these complex structures? The problem is exacerbated if we consider the realm of interactively controlled sound. This chapter presents an organization which, rather than forcing a particular way of thinking about sound, allows multiple arbitrarily high-level views to coexist, all sharing a common interface. The methods or algorithms are abstracted into a objects called auditory actors. This encapsulation allows different algorithms to be used concurrently. All communication with and between these actors is carried out through message-passing, which allows arbitrary types of information (such as other messages) to be easily communicated. This standardizes control without limiting it to a particular type of data. A prototype system was implemented using this model. This system was used by a number of diierent developers to create audio interfaces for interactive virtual reality applications, which were demonstrated at the SIGGRtlPH 94 conference in Orlando, Florida. Compared to earlier systems, developers were able to create more complex audio interfaces in a shorter time.