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US 2009/0154717 A1Published application
Echo Suppressing Method and Apparatus
AssigneeNEC Corporation
InventorOsamu Hoshuyama
Life of this patent
Estimating the term…
Abstract
Converter 100 uses either the output signal of a sound pickup device or the signal obtained by subtracting the output signal of an echo canceller from the output signal of the sound pickup device as a first signal, uses an estimated crosstalk value indicative of an estimated value of the amount of crosstalk of an echo leaking into the first signal to correct the first signal, and limits the corrected first signal not to be smaller than estimated near-end noise.
Claims24
1-25. (canceled)
An echo suppressing method comprising:
- using either the output signal of a sound pickup device or the signal obtained by subtracting the output signal of said sound pickup device after echo suppression from the output signal of said sound pickup device as a first signal;
- using the output signal after echo suppression as a second signal;
- multiplying said second signal transformed in a frequency domain by an estimated crosstalk value;
- and
- using the multiplication result to suppress the echo component in said first signal transformed in a frequency domain,
- wherein the suppressed first signal is limited not to be smaller than an estimated value of near-end noise estimated for each frequency range.
3 more elements
An echo suppressing apparatus for suppressing an echo generated by acoustic coupling between a sound pickup device and a loudspeaker, the apparatus comprising:
- an echo canceller that uses the input signal to said loudspeaker to estimate said echo;
- frequency dividers that use either the output signal of said sound pickup device or the signal obtained by subtracting the estimated echo from the input signal to said loudspeaker as a first signal, use the estimated echo as a second signal, and divide said first signal and said second signal into signals in predetermined frequency ranges;
- a noise estimator that estimates the value of near-end noise for each of the frequency ranges of the divided first signals;
- a corrector for each of said frequency ranges that uses said second signal and an estimated crosstalk value indicative of the degree of the echo left in said first signal to suppress the echo component in said first signal;
- a limiter that limits the corrected first signal not to be smaller than the estimated value of near-end noise estimated for each of the respective frequency ranges;
- and
- a frequency synthesizer that synthesizes the corrected first signals corrected for the respective frequency ranges and outputted from said limiter.
4 more elements
An echo suppressing apparatus for suppressing an echo generated by acoustic coupling between a sound pickup device and a loudspeaker, the apparatus comprising:
- a transform-domain echo canceller that uses the input signal to said loudspeaker to estimate said echo;
- a noise estimator that uses the signals obtained by dividing the signal obtained by subtracting the estimated echo from the input signal to said loudspeaker as a group of first signals, the division being carried out in said transform-domain echo canceller for each predetermined frequency range, uses the signals in the respective predetermined frequency ranges of the output signal of said transform-domain echo canceller as a group of second signals, and estimates the value of near-end noise for each of said frequency ranges of the group of first signals;
- a corrector for each of said frequency ranges that uses said second signal and an estimated crosstalk value indicative of the degree of the echo left in said first signal to suppress the echo component in said first signal;
- a limiter that limits the corrected first signal not to be smaller than the estimated value of near-end noise estimated for each of the respective frequency ranges;
- and
- a frequency synthesizer that synthesizes the corrected first signals corrected for the respective frequency ranges and outputted from said limiter.
3 more elements
An echo suppressing apparatus for suppressing an echo generated by acoustic coupling between a sound pickup device and a loudspeaker, the apparatus comprising:
- an echo canceller that uses the input signal to said loudspeaker to estimate said echo;
- subband analysis filters that expand the output signal of said sound pickup device and the input signal of said loudspeaker for each predetermined frequency range;
- a noise estimator that uses either the signals obtained by expanding the output signal of said sound pickup device for the respective frequency ranges or the signals obtained by subtracting the estimated echo from the signals obtained by expanding the input signal to said loudspeaker for the respective frequency ranges as a group of first signals, uses the estimated echo as a second signal, and estimates the value of near-end noise for each of the frequency ranges of the group of first signals;
- a corrector for each of said frequency ranges that uses said second signal and an estimated crosstalk value indicative of the degree of the echo left in said first signal to suppress the echo component in said first signal;
- a limiter that limits the corrected first signal not to be smaller than the estimated value of near-end noise estimated for each of the respective frequency ranges;
- and
- a frequency synthesizer that synthesizes the corrected first signals corrected for the respective frequency ranges and outputted from said limiter.
4 more elements
An echo suppressing apparatus for suppressing an echo generated by acoustic coupling between a sound pickup device and a loudspeaker, the apparatus comprising:
- an echo canceller that uses the input signal to said loudspeaker to estimate said echo;
- Fourier transformers that expand the output signal of said sound pickup device and the input signal to said loudspeaker for each predetermined frequency range;
- a noise estimator that uses either the signals obtained by expanding the output signal of said sound pickup device for the respective frequency ranges or the signals obtained by subtracting the estimated echo from the signals obtained by expanding the input signal to said loudspeaker for the respective frequency ranges as a group of first signals, uses the estimated echo as a second signal, and estimates the value of near-end noise for each of the frequency ranges of the group of first signals;
- a corrector for each of said frequency ranges that uses said second signal and an estimated crosstalk value indicative of the degree of the echo left in said first signal to suppress the echo component in said first signal;
- a limiter that limits the corrected first signal not to be smaller than the estimated value of near-end noise estimated for each of the respective frequency ranges;
- and
- a frequency synthesizer that synthesizes the corrected first signals corrected for the respective frequency ranges and outputted from said limiter.
4 more elements
Dependencies are inferred from the claim text.