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US 5,907,622 AGranted
Automatic noise compensation system for audio reproduction equipment
OwnerA. Michael Doughertyinventor
Life of this patent
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Abstract
The disclosed audio signal processing system produces an acoustic signal in a listening space and includes devices for generating a desired volume signal, a noise signal representative of ambient noise conditions in the listening space, and an audio signal. The system further includes a variable gain amplifier for amplifying the audio signal in response to a gain control signal and a device for generating the gain control signal in response to a volume control signal. The volume control signal is generated in response to the noise and desired volume signals so that the volume control signal increases in response to increases in the noise signal. The volume control signal increases at a rate of increase and the rate of increase decreases as the volume control signal increases.
Claims54
An audio signal processing system for application to an audio transducer to produce an acoustic signal in a listening space, comprising:
- A. means for generating a desired volume signal representative of a desired volume of said acoustic signal in said listening space;
- B. noise means for generating a noise signal representative of an ambient noise condition in the listening space;
- C. variable gain amplification means for receiving an audio signal and a gain control signal and for amplifying said audio signal in accordance with said gain control signal to generate an output signal;
- D. volume control means for generating a volume control signal in response to said desired volume signal and said noise signal, said volume control signal being representative of amplification corresponding to a monotonically increasing value as a function of increase of said ambient noise condition wherein the rate of increase as a function of said ambient noise condition is monotonically decreasing;
- and
- E. gain control means for generating said gain control signal in response to said volume control signal.
3 more elements
An audio signal processing system for application to an audio transducer to produce an acoustic signal in a listening space, comprising:
- A. means for generating a desired volume signal representative of a desired volume of said acoustic signal in said listening space;
- B. noise means for generating a noise signal representative of an ambient noise condition in the listening space;
- C. variable gain amplification means for receiving an audio signal and a gain control signal and for amplifying said audio signal in accordance with said gain control signal to generate an output signal;
- D. volume control means for generating a volume control signal in response to said desired volume signal and said noise signal, said volume control signal being representative of amplification (i) corresponding to a monotonically increasing value as a function of increase of said ambient noise condition wherein the rate of increase as a function of said ambient noise condition is monotonically decreasing, and (ii) corresponding to a monotonically increasing value as a function of increase of said desired volume wherein the rate of increase as a function of said desired volume is monotonically decreasing;
- and
- E. gain control means for generating said gain control signal in response to said volume control signal.
3 more elements
An audio signal processing system for application to an audio transducer to produce an acoustic signal in a listening space, comprising:
- A. means for generating a desired volume signal representative of a desired volume of said acoustic signal in said listening space;
- B. noise means for generating a noise signal representative of an ambient noise condition in the listening space;
- C. variable gain amplification means for receiving an audio signal and a gain control signal and for amplifying said audio signal in accordance with said gain control signal to generate an output signal;
- D. volume control means for generating a volume control signal, said volume control signal being representative of amplification corresponding to a monotonically increasing value as a function of increase of said ambient noise condition wherein the rate of increase as a function of said ambient noise condition is monotonically decreasing, including,
- i. memory means for storing a plurality of volume control values at locations therein, each of said volume control values being representative of a value of said volume control signal associated with a set of values of said desired volume signal, and said noise signal;
- ii. address means for generating an address signal in response to a current set of values of said desired volume level, and said noise signal, so that said address signal accesses a location of said memory means storing the volume control value associated with said current set of values;
- iii. volume control signal means, responsive to said address signal, for generating said volume control signal, said volume control signal corresponding to the volume control value associated with said current set of values;
- and
- E. gain control means for generating said gain control signal in response to said volume control signal.
6 more elements
An audio signal processing system for application to an audio transducer to produce an acoustic signal in a listening space, comprising:
- A. means for generating a desired volume signal;
- B. noise means for generating a noise signal representative of an ambient noise condition in the listening space;
- C. variable gain amplification means for receiving an audio signal and a gain control signal and for amplifying said audio signal in accordance with said gain control signal to generate an output signal;
- D. volume control means for generating a volume control signal representative of a maximum amplitude of said gain control signal;
- E. compression means for generating a power signal representative of a power level of said audio signal and for generating a compression setting signal in response to a difference between said volume control signal and said noise signal and for generating a compression signal as a product of said power signal and said compression setting signal;
- and
- E. gain control means for generating said gain control signal in response to said volume control signal and said compression signal.
4 more elements
An audio signal processing system for application to an audio transducer to produce an acoustic signal in a listening space, comprising:
- A. means for generating a desired volume signal representative of a desired volume of said acoustic signal in said listening space;
- B. means for generating a sensor signal representative of a current set of conditions of said listening space;
- C. volume control means for generating a volume control signal, said volume control signal being representative of amplification corresponding to a monotonically increasing value as a function of increase of said ambient noise condition wherein the rate of increase as a function of said ambient noise condition is monotonically decreasing, including,
- i. memory means for storing a plurality of volume control values at locations therein, each of said volume control values being representative of a value of said volume control signal associated with a set of values of said desired volume signal, and said sensor signal;
- ii. address means for generating an address signal in response to a current set of values of said desired volume level, and said sensor signal, so that said address signal accesses a location of said memory means storing the volume control value associated with said current set of values;
- iii. volume control signal means, responsive to said address signal, for generating said volume control signal, said volume control signal corresponding to the volume control value associated with said current set of values;
- and
- D. means for generating said acoustic signal in response to said volume control signal and an audio signal.
5 more elements
Dependencies are inferred from the claim text.