Patent ID: 9338576
Filing Date: 2016-05-10
CPC Classification: H04S

Claim Text:
1. An apparatus for listening room equalization, wherein the apparatus is adapted to receive a plurality of loudspeaker input signals, and wherein the apparatus comprises: a first transform unit for transforming the at least two loudspeaker input signals from a time domain to a wave domain to acquire a plurality of transformed loudspeaker signals, a system identification adaptation unit for adapting a first loudspeaker-enclosure-microphone system identification to acquire a second loudspeaker-enclosure-microphone system identification, wherein the first and the second loudspeaker-enclosure-microphone system identification identify a loudspeaker-enclosure-microphone system comprising a plurality of loudspeakers and a plurality of microphones, a filter, wherein the filter comprises a plurality of subfilters for generating a plurality of filtered loudspeaker signals, an inverse transform unit for transforming the plurality of filtered loudspeaker signals from the wave domain to the time domain to acquire filtered time-domain loudspeaker signals and for feeding the filtered time-domain loudspeaker signals into the plurality of loudspeakers of the loudspeaker-enclosure-microphone system, a filter adaptation unit for adapting the filter based on the second loudspeaker-enclosure-microphone system identification and based on a predetermined loudspeaker-enclosure-microphone system identification, wherein the system identification adaptation unit is configured to adapt the first loudspeaker-enclosure-microphone system identification based on an error indicating a difference between a plurality of transformed microphone signals and a plurality of estimated microphone signals, wherein the plurality of transformed microphone signals and the plurality of estimated microphone signals depend on the plurality of the filtered loudspeaker signals, wherein the filter is defined by a first matrix {tilde over (G)}(n), wherein the first matrix {tilde over (G)}(n) comprises a plurality of first matrix coefficients, wherein the filter adaptation unit is configured to adapt the filter by adapting the first matrix {tilde over (G)}(n), and wherein the filter adaptation unit is configured to adapt the first matrix {tilde over (G)}(n) by setting one or more of the plurality of first matrix coefficients to zero, a second transform unit for receiving a plurality of microphone signals as received by the plurality of microphones and for transforming a plurality of microphone signals of the loudspeaker-enclosure-microphone system from a time domain to a wave domain to acquire the plurality of transformed microphone signals, and a loudspeaker-enclosure-microphone system estimator for generating the plurality of estimated microphone signals based on the first loudspeaker-enclosure-microphone system identification and based on the plurality of the filtered loudspeaker signals, wherein each subfilter of the subfilters is arranged to receive one or more of the transformed loudspeaker signals as received loudspeaker signals of said subfilter, and wherein each subfilter of the subfilters is furthermore adapted to generate one of the plurality of filtered loudspeaker signals based on the one or more received loudspeaker signals of said subfilter, wherein at least one subfilter of the subfilters is arranged to receive at least two of the transformed loudspeaker signals as the received loudspeaker signals of said subfilter, and is furthermore arranged to couple the at least two received loudspeaker signals of said subfilter to generate one of the plurality of the filtered loudspeaker signals of said subfilter, wherein at least one subfilter of the subfilters comprises a number of the received loudspeaker signals of said subfilter that is smaller than a total number of the plurality of transformed loudspeaker signals, the number of the received loudspeaker signals of said subfilter being one or greater than one, and wherein, when the number of the received loudspeaker signals of a subfilter of the at least one of the subfilters is greater than one, only the received loudspeaker signals of the subfilter of the at least one of the subfilters are coupled to generate the one of the plurality of the filtered loudspeaker signals.