A digital signal processing audiometric workstation

The authors report on the development of a digital signal processing audiometric workstation based on a standard IBM PC and Motorola DSP56001 processor. The current system has functionality to test a patient´s hearing using pure tone testing, FM tones, bandlimited noise, speech and white noise signals. Unlike most consumer DSP audio systems, the workstation uses 24 bit digital signals, which are then converted to analogue signals in an effort to produce a dynamic range much wider than the 88 dB nominally achieveable with 16 bit systems. Aside from the low level DSP functionality, the audiometric workstation has also been designed to be very easy to use by developing a Windows 3.1 based interface to provide a virtual instrument by duplicating the controls of a standard audiometer on screen