Microcomputer based data acquisition and analysis systems for graduate student research in Acoustics

The development and commercial availability of dedicated multichannel fast‐Fourier transform (FFT) analyzers have resulted in a significant advancement in productivity in research in acoustics. The capability of at least two‐channel FFT instrumentation is a must for any acoustics laboratory; however, the acquisition of a single instrument represents a major item in a research budget. Two personal‐computer‐based multichannel FFT systems will be described and demonstrated. These systems are currently being used by graduate students in theses research in internal combustion engine noise and in piping system noise. These relatively low‐cost systems were assembled with commercially available data acquisition components and software. Microphone signal conditioning preamplifiers and anti‐aliasing filters were designed by a senior electrical engineering student. Preamplifier gains and filter cutoff frequencies are controlled by the microcomputer.