Electrical audio signal processing systems and devices – One-way audio signal program distribution – Public address system
Patent
1989-10-18
1991-08-13
Kemeny, Emanuel S.
Electrical audio signal processing systems and devices
One-way audio signal program distribution
Public address system
G10L 500
Patent
active
050402170
ABSTRACT:
A method is disclosed for determining estimates of the perceived noise masking level of audio signals as a function of frequency. By developing a randomness metric related to the euclidian distance between (i) actual frequency components amplitude and phase for each block of sampled values of the signal and (ii) predicted values for these components based on values in prior blocks, it is possible to form a tonality index which provides more detailed information useful in forming the noise masking function. Application of these techniques is illustrated in a coding and decoding context for audio recording or transmission. The noise spectrum is shaped based on a noise threshold and a tonality measure for each critical frequency-band (bark).
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Brandenburg Karlheinz
Johnston James D.
AT&T Bell Laboratories
Kemeny Emanuel S.
Ryan W.
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