Method for improving acoustic sidetone suppression in hands-free telephones
AssigneeInfineon Technologies AG
InventorGerhard Schmidt
Life of this patent
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Abstract
A method for improving acoustic sidetone suppression in hands-free telephones, in particular for use in motor vehicles, is described. The telephone has a level discriminator and a plurality of adaptive echo compensation filters each processing a subband. In at least one subband, a further adaptive filter (a shadow filter) of a lower order is connected in parallel with the adaptive echo compensation filter. Spatial changes are detected with the aid of a combined evaluation of a correlation analysis and a residual error comparison of the two competing, adaptive filters.
Claims10
A method for improving acoustic sidetone suppression, which comprises the steps of:
- providing a hands-free telephone having a level discriminator and a plurality of adaptive echo compensation filters each processing a subband;
- connecting a further adaptive filter of a different order in parallel with an adaptive echo compensation filter of the adaptive echo compensation filters in at least one half band;
- and
- detecting spatial changes using a correlation analysis and a power evaluation of an output of the further adaptive filter.
Dependencies are inferred from the claim text.