ABSTRACT
Background and Objective: Fast and reliable methods of synthesizing various auditory stimuli have been demanded both in clinical and in experimental auditory evaluations. Computerized digital stimulus synthesis system was developed to achieve the accuracy of stimulus waveforms, the simplicity of controlling stimulus parameters, and the flexibility of generating complex stimuli. MATERIALS AND METHODS: The system consisted of an AD / DA Board (GW Instrument), Macintosh computer system (Apple Computer Inc), and custom-made timing devices to digitally synthesize auditory stimuli. Developed programs controlled various parameters of this hardware system in real time. RESULTS: The system generated pure tones (default frequency range: 0.001-25000 Hz), harmonic stacks (components up to 10 tones), white noises (with various Gaussian variances). These synthesized stimuli were controlled by systematically varying presentation parameters such as rise / fall times, presentation duration, repetition rates, and phase relationship between frequencies. Conclusions: This stimulus synthesis tool was fast, exact, and versatile in generating and controlling stimuli for the audiological evaluation.