Perceptual audio compression based on loudness uncertainty

Details Perceptual audio compression based on loudness uncertainty Perceptual audio compression based on loudness uncertainty

1995-02-06

1997-10-28

Safourek, Benedict V.

Pulse or digital communications

Repeaters

Testing

375240, H04B 166

Patent

active

056824637

ABSTRACT:
A new technique for the determination of the masking effect of an audio signal is employed to provide transparent compression of an audio signal at greatly reduced bit rates. The new technique employs the results of recent research into the psycho-physics of noise masking in the human auditory system. This research suggests that noise masking is a function of the uncertainty in loudness as perceived by the brain. Measures of loudness uncertainty are employed to determine the degree to which audio signals are "tone-like" (or "noise-like"). The degree of tone-likeness, referred to as "tonality," is used to determine masking thresholds for use in the compression of audio signals. Tonality, computed in accordance with the present invention, is used in conventional and new arrangements to achieve compression of audio signals.

REFERENCES:
patent: 5040217 (1991-08-01), Brandenburg et al.
patent: 5157760 (1992-10-01), Akagiri
patent: 5227788 (1993-07-01), Johnston et al.
patent: 5285498 (1994-02-01), Johnston et al.
patent: 5311561 (1994-05-01), Akagiri
patent: 5341457 (1994-08-01), Hall et al.
patent: 5375189 (1994-12-01), Tsutsui
patent: 5490170 (1996-02-01), Akagiri et al.
U.S. application No. 07/844819, (Ferreira 1-15), filed Mar. 2, 1992.
U.S. application No. 07/844811, (Johnston 16), filed Mar. 2, 1992.
U.S. application No. 08/384097, (Allen 13-5-37-2), filed Feb. 6, 1995.
Allen, J.B., "Cochlear Micromechanics -A Physical Model of Transduction," J. Acoust. Soc. Am., vol.68, pp. 1660-1670 (1980).
Allen et al., J. Acoust. Soc. Am., vol. 95, pp. 3006 (1994).
Buus, S., "Level Discrimination of Frozen and Random Noise," J. Acost. Soc. Am., vol. 87, No. 6, pp. 2643-2654, Jun. 1990.
Edler, "Coding of Audio Signals with Overlapping Block Transform and Adaptive Window Functions," Frequenz, vol. 43, pp. 252-256(1989).
Hellman, W. S. et al., "Intensity Discrimination as the Driving Force for Loudness," J. Acoust. Soc. Am., vol. 87, No. 3, pp. 1255-1265, Mar. 1990.
Johnston et al., "Wideband Coding-Perceptual Considerations for Speech and Music," Advances in Speech Signal Processing, Furui et al., ed. (1992).
Johnston et al., "Sum-Difference Stereo Transform Coding," Proc. of IEEE, ICASSP, San Francisco, II-569-572 (1992).
Schroeder, M. R. et al., "Optimizing Digital Speech Coders by Exploiting Masking Properties of the Human Ear," J. Acoustic Soc. Am., vol. 66, No. 6, pp. 1647-1652, Dec. 1979.
Teich, M. C. et al., "Pulse-number Distribution for the Neural Spike Train in the Cat's Auditory Nerve," J. Acoust. Soc. Am., vol. 77, pp. 1110-1128, 1985.

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