EP0466190A2
Expired / Lapsed
EP
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Quantizing error reducer for audio signal
Assignee: Sony Corp
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Filing: 1991-07-12
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Granted: —
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Expires: 2011-07-12
Abstract
Abstract The quantizing error or noise reducer for an audio signal feeds a quantizing error back to the input side of a quantizer (11) through a noise filter (13), wherein the filter coefficients are set on the basis of information relating to the equi-loudness curve, thereby making it possible to reduce the noise in the hearing sense.
Inventors
- 👤 Kenzo C/O Sony Corporation Akagiri
- 👤 Makoto C/O Sony Corporation Akune
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 20:30
CPC Classifications
H; H04; H04B; H04B14/00; H04B14/02; H04B14/04; H04B14/046; G; G11; G11B; G11B20/00; G11B20/10; G11B20/10527; H04B1/00; H04B1/66; H04B1/665
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
106 words
A quantizing noise reducer for an audio signal comprising: quantizing means (11) for quantizing an input audio signal, subtracter means (12) for subtracting an input signal to said quantizing means from an output signal from said quantizing means, filter means (13) supplied with an output from said subtracter means, synthesizing means (10) for synthesizing an output from said filter means and said input audio signal, and filter control means (14,15) for controlling the characteristic of said filter means, and including filter coefficient calculating means and data generating means for generating data relating to an equi-loudness characteristic, said data being supplied to said filter coefficient calculating means.
Claim 2
Dependent Claim
31 words
A quantizing noise reducer according to claim 1, wherein said filter control means further includes means for generating control data for correcting a lower frequency band portion of said filter characteristic.
Claim 3
Dependent Claim
32 words
A quantizing noise reducer according to claim 1, wherein said filter control means further includes means for controlling said filter characteristic in accordance with the masking effect of said input audio signal.
Claim 4
Dependent Claim
52 words
A quantizing noise reducer according to claim 3, wierein said filter control means conducts a control to present a filter characteristic to realize a noise shaping such that an allowable noise spectrum obtained in consideration of the temporal masking effect is provided in accordance with the spectrum of said input audio signal.
Claim 5
Dependent Claim
55 words
A quantizing noise reducer according to claim 3, wherein said filter control means conducts a control to present a filter characteristic to realize a noise shaping such that an allowable noise spectrum obtained in consideration of the masking effect on the time base is provided in accordance with the spectrum of said input audio signal.
Claim 6
Dependent Claim
81 words
A quantizing noise reducer according to claim 3, wherein said filter control means conducts a control to present a filter characteristic to realize a noise shaping such that an allowable noise spectrum in which the equi-loudness curve is taken into consideration when the signal level of said input audio signal is small and the making effect is taken into consideration according as the signal level thereof becomes large is provided in accordance with said signal level of said input audio signal.
References Cited (Backward Citations)
No citation records indexed.
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