Last Updated: 20050401, meiMonday, May 30, 17:00 — 18:30
Chair: Malcolm Hawksford, University of Essex - Colchester, Essex, UK
O-1 Differences of Hearing Impressions among Several High Sampling Digital Recording Formats—Toshiyuki Nishiguchi, Kimio Hamasaki, NHK Science & Technical Research Laboratories - Tokyo, Japan
To study the difference of hearing impression of recorded sound among several high sampling digital recording formats, we conducted subjective evaluation tests. Perceptual discrimination was evaluated among the following digital recording formats: 24-bit/48-kHz, 24-bit/192-kHz, and DSD. The sound reproduction system for the subjective evaluation tests was carefully designed in order to reproduce the highest quality of sound on each digital recording format. Listening panels were selected from students of a university of music, recording engineers, and musicians. Sound stimuli for the evaluation were originally recorded to have exactly the same quality of analog signal that was fed to different A/D conversion systems. The results of subjective evaluation using the pair test method showed that the sound quality of the auditory frequency band in this experimental system might not depend on the sampling format.
Convention Paper 6469 (Purchase now)
O-2 DSD Compression for Recent Ultra High Quality 1-Bit Coders—Erwin Janssen, Derk Reefman, Philips Research - Eindhoven, The Netherlands
This paper gives a high level introduction to the lossless DSD compression algorithm, used within the context of Super Audio CD, and currently in the process of MPEG standardization. The performance of the algorithm in terms of compression gain and achievable playing time is illustrated by measurement results on various commercially available discs. Typical playing times are around 75 minutes for discs comprising both stereo and multichannel material and around five hours for stereo-only material. Furthermore, the flexibility of the DSD/DST combination is demonstrated by the introduction of a new Trellis-based Sigma Delta Modulator (SDM). This modulator shows a 400 percent higher computational efficiency than a previously reported work and eliminates distortion and noise modulation completely. Ultra high quality DSD generation is shown and its compression performance is discussed. An average playing time of 80 to 90 minutes is realized for discs containing both stereo and multichannel audio. For stereo-only discs, a playing time of five to five and a half hours is demonstrated.
Convention Paper 6470 (Purchase now)
O-3 SDM versus PWM Power Digital-to-Analog Converters (PDAC) in High-Resolution Digital Audio Applications—Malcolm Hawksford, University of Essex - Colchester, Essex, UK
Sigma-delta modulation (SDM) and pulse-width modulation (PWM) are compared as a means of structuring power digital-to-analog converters (PDAC) designed specifically for wide-band audio, low power loss, and direct loudspeaker dive. Recent innovations in SDM coding and output-stage topologies using pulse shaping techniques are discussed with emphasis on achieving stable and low distortion operation especially under high-level signal excitation having a modulation index circa 0.7 necessary to process peak transients. A simplified variant of predictive SDM with step back is introduced that offers both low latency and probability of instability and structures for both analog and digital input data reviewed.
Convention Paper 6471 (Purchase now)
©2005 Audio Engineering Society, Inc.