ASA 124th Meeting New Orleans 1992 October

4pPPa21. Virtual instrument implementation of a one-third-octave-band analyzer.

John Hanks

David Koenig

Qiuhong Yang

Natl. Instrum., 6504 Bridge Point Pkwy., Austin, TX 78730

Virtual instrumentation, using software application tools and off the shelf plug-in cards to turn your computer into an instrument, is a very economical, attractive, and flexible method to perform audio analysis. Plug-in digital signal processing (DSP) boards provide personal computers with a level of processing power that was once restricted to all but the most powerful mainframe computers. These boards transform the PC into a parallel processing environment, delivering millions of floating point operations per second (MFLOPS) or more to numerically intensive tasks. Couple this with high-quality A/D converters and virtual instrumentation software tools and you have a powerful environment for building applications ranging from digital audio to underwater acoustics to vibration and modal analysis. This paper details a real-time acquisition and analysis DSP application using a 16-bit delta-sigma A/D converter and an AT&T WE DSP32C-based plug-in board to acquire and process restricted band audio frequency (dc to 5 kHz) information. A real-time restricted band one-third-octave analyzer was implemented using a AT computer and a plug-in board equipped with a digital signal processor and an audio frequency A/D converter. The restricted band one-third-octave analyzer provides the AT computer with enough power to meet or replace several stand-alone one-third-octave analyzers, and virtual instrumentation tools allow ease of configuration for new applications.