Hands-free telephony and in-vehicle communication

A processing system for a combined hands-free telecommunication and in-vehicle communication system for a vehicle, the processing system including an adaptive echo compensation filtering system, wherein the system is configured to:

• receive, by a hands-free set, a telephone signal from a party remote from the vehicle;
• receive, by an in-vehicle microphone of the in-vehicle communication system, a microphone signal from an occupant of the vehicle;
• detect speech activity in the telephone signal;
• reduce amplification of the microphone signal when speech activity is present in the telephone signal;
• and
• adapt the filter coefficients of the echo compensation filtering system only when output of the microphone signal is reduced to a predetermined level,
• wherein the processing system is configured to receive multiple microphone signals in multiple channels and to amplify the multiple microphone signals to obtain multiple first output signals, further comprising:
• a power estimating module configured to estimate the short-time power density of the multiple first output signals and to supply the maximum of the short-time power densities of the multiple first output signals to the hands-free set;
• and wherein the processing system is configured to determine whether the at least one first output signal output by the in-vehicle communication system is reduced to the predetermined level based on the maximum of the short-time power densities of the multiple first output signals.

A processing system for a combined hands-free telecommunication and in-vehicle communication system for a vehicle, the processing system configured to:

• receive, by a hands-free set, a telephone signal from a party remote from the vehicle;
• receive, by an in-vehicle microphone of the in-vehicle communication system, a microphone signal from an occupant of the vehicle;
• detect speech activity in the telephone signal;
• and
• reduce amplification of the microphone signal when speech activity is present in the telephone signal, wherein the processing system further comprises:
• a first equalization filter module configured to equalize microphone signals obtained by at least one microphone and input in the hands-free set and to adapt the filter coefficients of the first equalization filter module in the sub-band or Fourier domain;
• and
• a second equalization filtering module configured to equalize microphone signals input in the in-vehicle communication system and to adapt the filter coefficients of the second equalization filtering module in the time domain based on the adapted filter coefficients of the first equalization filtering module.

A method for reducing amplification of a microphone signal of an in-vehicle communication system, comprising:

• receiving a telephone signal from a party remote from the vehicle;
• receiving, by an in-vehicle microphone, a microphone signal from an occupant of the vehicle;
• detecting speech activity in the telephone signal;
• reducing amplification of the microphone signal when speech activity is present in the telephone signal;
• detecting speech activity in microphone signals obtained by at least one of the set of microphones and input in the in-vehicle communication system by processing the microphone signals in the time domain by the in-vehicle communication system;
• and
• supplying a signal by the in-vehicle communication system to the hands-free set operating in the sub-band or Fourier domain that indicates speech activity or no speech activity present in the microphone signal in response to the step of speech detection.

A method for reducing amplification of a microphone signal of an in-vehicle communication system having a hands-free set, comprising:

• receiving a telephone signal from a party remote from the vehicle;
• receiving, by an in-vehicle microphone, a microphone signal from an occupant of the vehicle;
• detecting speech activity in the telephone signal;
• and
• reducing amplification of the microphone signal when speech activity is present in the telephone signal;
• wherein the hands-free set comprises a first equalization filtering module configured to equalize microphone signals obtained by at least two of a set of microphones and input in the hands-free set;
• the in-vehicle communication system comprises a second equalization filtering module configured to equalize microphone signals input in the in-vehicle communication system;
• the method further comprising the steps of:
• adapting the filter coefficients of the first equalization filtering module in the sub-band or Fourier domain;
• and adapting the filter coefficients of the second equalization filtering module in the time domain based on the adapted filter coefficients of the first equalization filtering module.

A combined hands-free telecommunication and in-vehicle communication system, comprising:

• a plurality of microphones;
• a plurality of speakers;
• and
• a signal processing system configured to:
• receive, by a hands-free set, a telephone signal from a party remote from the vehicle;
• receive, by an in-vehicle microphone of the in-vehicle communication system, a microphone signal from an occupant of the vehicle;
• detect speech activity in the telephone signal;
• reduce amplification of the microphone signal when speech activity is present in the telephone signal;
• receive multiple microphone signals in multiple channels and to amplify the multiple microphone signals to obtain multiple first output signals, the system further comprising:
• a power estimating module configured to estimate the short-time power density of the multiple first output signals and to supply the maximum of the short-time power densities of the multiple first output signals to the hands-free set;
• and wherein the processing system is further configured to determine whether the at least one first output signal output by the in-vehicle communication system is reduced to the predetermined level based on the maximum of the short-time power densities of the multiple first output signals;
• the system further comprising:
• a first equalization filter module configured to equalize microphone signals obtained by at least one microphone and input in the hands-free set and to adapt the filter coefficients of the first equalization filter module in the sub-band or Fourier domain;
• and a second equalization filtering module configured to equalize microphone signals input in the in-vehicle communication system and to adapt the filter coefficients of the second equalization filtering module in the time domain based on the adapted filter coefficients of the first equalization filtering module,
• wherein the system is further configured to receive multiple microphone signals in multiple channels and to amplify the multiple microphone signals to obtain multiple first output signals, the system further comprising:
• a power estimating module configured to estimate the short-time power density of the multiple first output signals and to supply the maximum of the short-time power densities of the multiple first output signals to the hands-free set;
• and wherein the processing system is configured to determine whether the at least one first output signal output by the in-vehicle communication system is reduced to the predetermined level based on the maximum of the short-time power densities of the multiple first output signals.