PC software library for the production of auditory stimuli in cognitive event-related potential experiments

Software which provides an interface to the features of the Sound Blaster Pro card for the IBM PC using MS-DOS is described. The library may be called from a Turbo Pascal version 6 program. It permits tones of specified frequency (500 Hz-8 kHz in increments of 500Hz) and aversive noise to be turned on and off by a controlling program, during cognitive event-related potential paradigms. Tones are synthesized by hardware and noise is replayed from memory using the digital sound processor. The library provides the appropriate level of abstraction for the programmer designing such paradigms, by hiding the detail of the register level. It provides a model for programming the card in other high level languages and may be augmented to provide more complex stimuli, such as short segments of speech or music. The card when controlled by the library provides a versatile and cost effective alternative to an audiometer in the electrophysiological laboratory.