Apparatus and method for echo attenuation

Claim 1

A method for attenuating echo in a telephone comprising: measuring ambient background noise for a first telephone (10) for determining a noise level; setting attenuation parameters corresponding to the noise level; measuring a signal level received from a second telephone (11); calculating the attenuation for an output signal from the first telephone (10) corresponding to the attenuation parameters and the level of the received signal; and attenuating the output signal based upon the calculated attenuation; wherein the attenuation parameters are derivable from a plurality of attenuation parameter sets, from which a most suitable set is selected corresponding to the determined noise level, predetermined background noise threshold values that have been set, and the received signal.

Claim 2

A method for attenuating echo in a telephone comprising: measuring ambient background noise for a first telephone (10) for determining a noise level; setting attenuation parameters corresponding to the noise level; measuring a signal level received from a second telephone (11); calculating the attenuation for an output signal from the first telephone (10) corresponding to the attenuation parameters and the level of the received signal; and attenuating the output signal based upon the calculated attenuation; wherein the attenuation parameters are derivable from a plurality of attenuation parameter sets, from which a most suitable set is selected corresponding to the determined noise level, predetermined background noise threshold values that have been set, and the received signal.

Claim 6

An Apparatus for attenuating echo in a telephone, comprising: a noise detector (1) for detecting background noise; a background noise measurement unit (2) for determining a measured noise value; a parameter value determining unit (3), to which the measured noise value is fed from the background noise measurement unit (2); an input signal level measurement unit (4); an output signal attenuation determining unit (5), having inputs connected to the parameter determining unit (3) and the input signal level measurement unit (4); and an attenuation control unit (6) for adjusting the output signal level in accordance with the parameter values and the input signal level.

Claim 7

An Apparatus for attenuating echo in a telephone, comprising: a noise detector (1) for detecting background noise; a background noise measurement unit (2) for determining a measured noise value; a parameter value determining unit (3), to which the measured noise value is fed from the background noise measurement unit (2); an input signal level measurement unit (4); an output signal attenuation determining unit (5), having inputs connected to the parameter determining unit (3) and the input signal level measurement unit (4); and an attenuation control unit (6) for adjusting the output signal level in accordance with the parameter values and the input signal level.

Claim 11

A method for attenuating echo in a telephone comprising: measuring ambient background noise for a first telephone for determining a noise level; setting attenuation parameters corresponding to the noise level; measuring a signal level received from a second telephone; calculating an attenuation for an output signal from the first telephone corresponding to the attenuation parameters and the level of the received signal and attenuating the output signal based upon a calculated attenuation; wherein the step of setting comprises the steps of comparing the noise level to preset threshold values, each of the preset threshold values correlating with a respective number of attenuation parameters; and selecting the respective number of attenuation parameters which correspond to an Nth one of the threshold values exceeded by the noise level, for a case in which the noise level does not exceed an (N+1)th one of the threshold values.

Claim 12

A method for attenuating echo in a telephone comprising: measuring ambient background noise for a first telephone for determining a noise level; setting attenuation parameters corresponding to the noise level; measuring a signal level received from a second telephone; calculating an attenuation for an output signal from the first telephone corresponding to the attenuation parameters and the level of the received signal and attenuating the output signal based upon a calculated attenuation; wherein the step of setting comprises the steps of comparing the noise level to preset threshold values, each of the preset threshold values correlating with a respective number of attenuation parameters; and selecting the respective number of attenuation parameters which correspond to an Nth one of the threshold values exceeded by the noise level, for a case in which the noise level does not exceed an (N+1)th one of the threshold values.

Claim 15

An apparatus for attenuating echo in a telephone having a microphone, said apparatus being located within the telephone, comprising: a noise detector having an input connected to an output of said microphone, said noise detector for detecting whether a signal received by said microphone comprises speech or background noise; a background noise measurement unit having an input coupled to an output of said noise detector, said background noise measurement unit for measuring the level of background noise included in a signal output by said noise detector; a parameter determining unit for determining attenuation parameters based upon the level of background noise measured by said background noise measurement unit; an input signal measuring unit for measuring the level of speech included in a signal received by said telephone from another communication device; an attenuation determining unit for calculating, based upon an output of said input signal measuring unit and an output of said parameter determining unit, an attenuation required for a signal that is to be transmitted by said telephone; and an attenuation control unit for attenuating, based upon an attenuation calculated by said attenuation determining unit, the signal that is to be transmitted by said telephone.

Claim 16

An apparatus for attenuating echo in a telephone having a microphone, said apparatus being located within the telephone, comprising: a noise detector having an input connected to an output of said microphone, said noise detector for detecting whether a signal received by said microphone comprises speech or background noise; a background noise measurement unit having an input coupled to an output of said noise detector, said background noise measurement unit for measuring the level of background noise included in a signal output by said noise detector; a parameter determining unit for determining attenuation parameters based upon the level of background noise measured by said background noise measurement unit; an input signal measuring unit for measuring the level of speech included in a signal received by said telephone from another communication device; an attenuation determining unit for calculating, based upon an output of said input signal measuring unit and an output of said parameter determining unit, an attenuation required for a signal that is to be transmitted by said telephone; and an attenuation control unit for attenuating, based upon an attenuation calculated by said attenuation determining unit, the signal that is to be transmitted by said telephone.

Claim 20

An apparatus for attenuating echo in a telephone having a microphone, said apparatus being located within the telephone, comprising: a noise detector having an input connected to an output of said microphone, said noise detector for detecting whether a signal received by said microphone comprises speech or background noise; a background noise measurement unit having an input coupled to an output of said noise detector, said background noise measurement unit for measuring the level of background noise included in a signal output by said noise detector; a parameter determining unit for determining attenuation parameters based upon the level of background noise measured by said background noise measurement unit; an input signal measuring unit for measuring the level of speech included in a signal received by said telephone from another communication device; an attenuation determining unit for calculating, based upon an output of said input signal measuring unit and an output of said parameter determining unit, an attenuation required for a signal that is to be transmitted by said telephone; and an attenuation control unit for attenuating, based upon an attenuation calculated by said attenuation determining unit, the signal that is to be transmitted by said telephone; wherein the parameter determining unit has a range of preset threshold values and a number of attenuation parameters stored therein, and wherein each of the preset threshold values correlates with a respective at least one of the attenuation parameters.

Claim 21

An apparatus for attenuating echo in a telephone having a microphone, said apparatus being located within the telephone, comprising: a noise detector having an input connected to an output of said microphone, said noise detector for detecting whether a signal received by said microphone comprises speech or background noise; a background noise measurement unit having an input coupled to an output of said noise detector, said background noise measurement unit for measuring the level of background noise included in a signal output by said noise detector; a parameter determining unit for determining attenuation parameters based upon the level of background noise measured by said background noise measurement unit; an input signal measuring unit for measuring the level of speech included in a signal received by said telephone from another communication device; an attenuation determining unit for calculating, based upon an output of said input signal measuring unit and an output of said parameter determining unit, an attenuation required for a signal that is to be transmitted by said telephone; and an attenuation control unit for attenuating, based upon an attenuation calculated by said attenuation determining unit, the signal that is to be transmitted by said telephone; wherein the parameter determining unit has a range of preset threshold values and a number of attenuation parameters stored therein, and wherein each of the preset threshold values correlates with a respective at least one of the attenuation parameters.