Method and apparatus for dynamic sound optimization
First Claim
1. An audio enhancement system for compensating for ambient noise in a listening environment, comprising:
- A. an audio signal source for producing an electrical sound signal;
B. a loudspeaker for generating a sound output from said electrical sound signal;
C. a microphone adapted for placement in a listening environment to provide a total sound signal representative of the total sound level in said environment, wherein said total sound level comprises both the sound output from said loudspeaker and the ambient noise within said environment;
D. a signal processor for subtracting said sound output from said total sound signal, thereby extracting an ambient noise signal representative of said ambient noise;
E. a gain calculator for comparing said electrical sound signal from said audio signal source with said ambient noise signal and determining their relative levels; and
F. at least a first volume control responsive to the relative levels of the electrical sound signal and the ambient noise signal for adjusting said sound output of said loudspeaker to compensate for said ambient noise.
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Accused Products
Abstract
This invention comprises a system to compensate for the noise level inside a vehicle by measuring the music level and the noise level in the vehicle through the use of analog to digital conversion and adaptive digital filtering, including a sensing microphone in the vehicle cabin to measure both music and noise; preamplification and analog to digital (A/D) conversion of the microphone signal; A/D conversion of a stereo music signal; a pair of filters that use an adaptive algorithm such as the known Least Mean Squares ("LMS") method to extract the noise from the total cabin sound; an estimation of the masking effect of the noise on the music; an adaptive correction of the music loudness and, optionally, equalization to overcome the masking effect; digital to analog (D/A) conversion of the corrected music signal; and transmission of the corrected music signal to the audio system.
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Citations
29 Claims
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1. An audio enhancement system for compensating for ambient noise in a listening environment, comprising:
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A. an audio signal source for producing an electrical sound signal; B. a loudspeaker for generating a sound output from said electrical sound signal; C. a microphone adapted for placement in a listening environment to provide a total sound signal representative of the total sound level in said environment, wherein said total sound level comprises both the sound output from said loudspeaker and the ambient noise within said environment; D. a signal processor for subtracting said sound output from said total sound signal, thereby extracting an ambient noise signal representative of said ambient noise; E. a gain calculator for comparing said electrical sound signal from said audio signal source with said ambient noise signal and determining their relative levels; and F. at least a first volume control responsive to the relative levels of the electrical sound signal and the ambient noise signal for adjusting said sound output of said loudspeaker to compensate for said ambient noise. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An audio enhancement system for compensating for ambient noise in a listening environment, comprising
A. an audio signal source for producing an electrical sound signal; -
B. a splitter for separating said electrical sound signal into a first component and a second component, said first component being substantially identical in all respects to said second component; C. a loudspeaker for generating a sound output from said second component of said electrical sound signal; D. a microphone adapted for placement in a listening environment to provide a total sound signal representative of the total sound level in said environment, wherein said total sound level comprises both said sound output from said loudspeaker and the ambient noise within said environment; E. an analog-to-digital converter for converting said first component of said electrical sound signal and said total sound signal from analog signals to digital signals; F. a signal processor for subtracting said sound output from said total sound signal, thereby extracting an ambient noise signal representative of said ambient noise; G. a gain calculator for comparing said first component of said electrical sound signal with said ambient noise signal; and H. at least a first volume control responsive to the relative levels of the first component of said electrical sound signal and the ambient noise signal for adjusting said sound output of said loudspeaker to compensate for said ambient noise level. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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21. An audio enhancement system for compensating for ambient noise in a listening environment, comprising
A. an audio signal source for producing an electrical sound signal; -
B. a loudspeaker for generating a sound output from said electrical sound signal; C. a microphone adapted for placement in a listening environment to provide a total sound signal representative of the total sound level in said environment, wherein said total sound level comprises both the sound output from said loudspeaker and the ambient noise within said environment; D. a splitter for splitting said electrical sound signal from said audio signal source into at least a first and a second electrical sound signal, said first and second electrical sound signals having different frequencies; E. a signal processor for extracting an ambient noise signal representative of the ambient noise level in said environment from said total sound signal; F. a gain calculator for comparing said first electrical sound signal with said ambient noise signal and for comparing said second electrical sound signal with said ambient noise signal; and G. at least one volume control responsive to said gain calculator for adjusting the output of said audio signal source to compensate for said ambient noise level. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
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Specification