| This paper details the design and fabrication of an audio frequency data acquisition and analysis system, and its subsequent use to investigate the qualitative effects of sampling rate and bit resolution of streaming digital audio.; The data acquisition system is fabricated in an industry standard Peripheral Component Interconnect form factor and resides within a Personal Computer. In addition to the data conversion circuitry, the card also contains 256 Mbytes of data acquisition memory and a high performance, floating-point Digital Signal Processor for (optional) real-time signal analysis of the sampled data. The host computer controls the overall operation of the data acquisition card and transfers sampled data/streaming digital audio to and from the card. The host also performs the non-real-time signal analysis of the sampled data and displays the analysis results. The data acquisition system supports sampling rates from 32 kHz to 192 kHz, and sampling resolutions from 8-bits to 24-bits.; The first application of the completed data acquisition system is the analysis of the perceived audio quality (with respect to the sampling rate and data resolution) of standard Compact Disc digital audio. While the depth of the analysis has been limited by practical constraints of time, resources, and facilities, the results of this investigation indicate that “Compact Disc quality” audio can indeed be measurably improved by either increasing the sampling rate or extending the resolution, or (ideally) by doing both. |
