Direct digital conversion in acoustic transducers
James L. Flanagan · The Journal of the Acoustical Society of America · 1979
We offer some views, some computer analyses, and some preliminary experimental measurements on acoustic transducers designed to operate directly with digital signals. In particular, we describe a condenser receiving element and acoustic filter system that functions directly as a digital-to-analog converter (DAC). The transducer accepts the binary digital signal of PCM-encoded speech and produces the decoded analog acoustic output. We also suggest a design for a transducer that performs the reverse operation, that is, analog-to-digital conversion (ADC). Initial results are very tentative; many problems remain. But the techniques hint at routes to digital communication that can obviate, at least to some extent, the expense and complexity of conventional ADC and DAC circuitry.