Electrical audio signal processing systems and devices – One-way audio signal program distribution – Public address system
Patent
1987-04-01
1990-02-27
Harkcom, Gary V.
Electrical audio signal processing systems and devices
One-way audio signal program distribution
Public address system
G10L 708
Patent
active
049052861
ABSTRACT:
In speech recognition it is advantageous to take account of noise levels both in recognition and training. In both processes signals reaching a microphone are digitized and passed through a filter bank to be separated into frequency channels. In training, a noise estimator and a masker are used with a recognizer to prepare and store probability density functions (p.d.f.s) for each channel partially defining Markov models of words to be recognized. The p.d.f.s are derived only from input signals above noise levels but derivation is such that the whole of each p.d.f. is represented. In recognition, "distance" measurements on which recognition is based are derived for each channel. If the signal in a channel is above noise then the distance is determined, by the recognizer, from the negative logarithm of the p.d.f. but if a channel signal is below noise then the distance is determined from the negative logarithm of the cumulative distance of the p.d.f. to the noise level.
REFERENCES:
patent: 4239936 (1980-12-01), Sakoe
patent: 4587670 (1986-05-01), Levison et al.
patent: 4720802 (1988-01-01), Damoulakis et al.
J. N. Holmes et al., "Noise Compensation for Speech Recognition Using Probabilistic Models", ICASSP 86, Proceedings of the International Conference on Acoustics, Speech and Signal Processing, 7th-11th Apr. 1986, pp. 741-744, IEEE, Tokyo, Japan.
Klatt, "A Digital Filter Bank for Spectral Subtraction", IEEE ICASSP 76, pp. 573-576.
Holmes John N.
Sedgwick Nigel C.
Harkcom Gary V.
Merecki John A.
National Research Development Corporation
LandOfFree
Noise compensation in speech recognition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Noise compensation in speech recognition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Noise compensation in speech recognition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-179705