Adaptive filter for speech enhancement in a noisy environment

A speech enhancement filter for improving clarity of a voice represented by an audio signal, said speech enhancement filter comprising:

• a first filter element that smooths a spectrum of the audio signal over larger windows at higher frequencies in accordance with a mel-scale to provide a smoothed audio signal;
• a second filter element that filters the smoothed audio signal with a causal Wiener filter to provide a Wiener filter result;
• and
• a third filter element that performs at one of temporal and frequency smoothing of the Wiener filter result to provide a filtered audio signal corresponding to a clarified version of the spoken voice.

A movable vehicle cabin having ambient noise, said cabin comprising:

• means for causing movement of said cabin, wherein at least a portion of the ambient noise during movement is a result of the movement;
• and
• a cabin communication system for improving clarity of a voice spoken within an interior of said cabin, wherein said cabin communication system comprises:
• a microphone for receiving the spoken voice and the ambient noise and for converting the spoken voice and the ambient noise into an audio signal, the audio signal having a first component corresponding to the spoken voice and a second component corresponding to the ambient noise;
• a speech enhancement filter for removing the second component from the audio signal to provide a filtered audio signal, said speech enhancement filter removing the second component by processing the audio signal by a method taking into account elements of psycho-acoustics of a human ear;
• and
• a loudspeaker for outputting a clarified voice in response to the filtered audio signal.

A movable vehicle cabin having ambient noise, said cabin comprising:

• means for causing movement of said cabin, wherein at least a portion of the ambient noise during movement is a result of the movement;
• and
• a cabin communication system for improving clarity of a voice spoken within an interior of said cabin, wherein said cabin communication system comprises:
• a microphone for receiving the spoken voice and the ambient noise and for converting the spoken voice and the ambient noise into an audio signal, the audio signal having a first component corresponding to the spoken voice and a second component corresponding to the ambient noise;
• a speech enhancement filter for removing the second component from the audio signal to provide a filtered audio signal;
• and
• a loudspeaker for outputting a clarified voice in response to the filtered audio signal,
• wherein said speech enhancement filter comprises:
• a first filter element that smooths a spectrum of the audio signal over larger windows at higher frequencies in accordance with a mel-scale to provide a smoothed audio signal;
• a second filter element that filters the smoothed audio signal with a causal Wiener filter to provide a Wiener filter result;
• and
• a third filter element that performs at one of temporal and frequency smoothing of the Wiener filter result to provide the filtered audio signal.

A cabin communication system for improving clarity of a voice spoken within an interior cabin having ambient noise, said cabin communication system comprising:

• a first microphone, positioned at a first location within the cabin, for receiving the spoken voice and the ambient noise and for converting the spoken voice into a first audio signal, the first audio signal having a first component corresponding to the ambient noise;
• a second microphone, positioned at a second location within the cabin, for receiving the spoken voice and the ambient noise and for converting the spoken voice into a second audio signal, the second audio signal having a second component corresponding to the ambient noise;
• a processor for summing the first and second audio signals to provide a resultant audio signal that is indicative of a detection location within the cabin relative to the first and second locations of said first and second microphones;
• a speech enhancement filter for filtering the resultant audio signal by removing the first and second components to provide a filtered audio signal;
• an echo cancellation system receiving the filtered audio signal and outputting an echo-cancelled audio signal;
• and
• a loudspeaker for converting the echo-cancelled audio signal into an output reproduced voice within the cabin including a third component indicative of the first and second audio signals,
• wherein said loudspeaker and said first and second microphones are acoustically coupled so that the output reproduced voice is fed back from said loudspeaker to be received by said first and second microphones and converted with the spoken voice into the first and second audio signals,
• wherein said echo cancellation system removes from the filtered audio signal any portion of the filtered audio signal corresponding to the third component, and
• wherein said speech enhancement filter removes the first and second components by processing the resultant audio signal by a method taking into account elements of psycho-acoustics of a human ear.

A cabin communication system for improving clarity of a voice spoken within an interior cabin having ambient noise, said cabin communication system comprising:

• a first microphone, positioned at a first location within the cabin, for receiving the spoken voice and the ambient noise and for converting the spoken voice into a first audio signal, the first audio signal having a first component corresponding to the ambient noise;
• a second microphone, positioned at a second location within the cabin, for receiving the spoken voice and the ambient noise and for converting the spoken voice into a second audio signal, the second audio signal having a second component corresponding to the ambient noise;
• a processor for summing the first and second audio signals to provide a resultant audio signal that is indicative of a detection location within the cabin relative to the first and second locations of said first and second microphones;
• a speech enhancement filter for filtering the resultant audio signal by removing the first and second components to provide a filtered audio signal;
• an echo cancellation system receiving the filtered audio signal and outputting an echo-cancelled audio signal;
• and
• a loudspeaker for converting the echo-cancelled audio signal into an output reproduced voice within the cabin including a third component indicative of the first and second audio signals,
• wherein said loudspeaker and said first and second microphones are acoustically coupled so that the output reproduced voice is fed back from said loudspeaker to be received by said first and second microphones and converted with the spoken voice into the first and second audio signals,
• wherein said echo cancellation system removes from the filtered audio signal any portion of the filtered audio signal corresponding to the third component, and
• wherein said speech enhancement filter comprises:
• a first filter element that smooths a spectrum of the resultant audio signal over larger windows at higher frequencies in accordance with a mel-scale to provide a smoothed audio signal;
• a second filter element that filters the smoothed audio signal with a causal Wiener filter to provide a Wiener filter result;
• and
• a third filter element that performs at one of temporal and frequency smoothing of the Wiener filter result to provide the filtered audio signal.

A movable vehicle cabin having ambient noise, said cabin comprising:

• means for causing movement of said cabin, wherein at least a portion of the ambient noise during movement is a result of the movement;
• and
• a cabin communication system for improving clarity of a voice spoken within an interior of said cabin, said cabin communication system comprising:
• a first microphone, positioned at a first location within the cabin, for receiving the spoken voice and the ambient noise and for converting the spoken voice into a first audio signal, the first audio signal having a first component corresponding to the ambient noise;
• a second microphone, positioned at a second location within the cabin, for receiving the spoken voice and the ambient noise and for converting the spoken voice into a second audio signal, the second audio signal having a second component corresponding to the ambient noise;
• a processor for summing the first and second audio signals to provide a resultant audio signal that is indicative of a detection location within the cabin relative to the first and second locations of said first and second microphones;
• a speech enhancement filter for filtering the resultant audio signal by removing the first and second components to provide a filtered audio signal;
• an echo cancellation system receiving the filtered audio signal and outputting an echo-cancelled audio signal;
• and
• a loudspeaker for converting the echo-cancelled audio signal into an output reproduced voice within the cabin including a third component indicative of the first and second audio signals,
• wherein said loudspeaker and said first and second microphones are acoustically coupled so that the output reproduced voice is fed back from said loudspeaker to be received by said first and second microphones and converted with the spoken voice into the first and second audio signals,
• wherein said echo cancellation system removes from the filtered audio signal any portion of the filtered audio signal corresponding to the third component, and
• wherein said speech enhancement filter removes the first and second components by processing the resultant audio signal by a method taking into account elements of psycho-acoustics of a human ear.

A movable vehicle cabin having ambient noise, said cabin comprising:

• means for causing movement of said cabin, wherein at least a portion of the ambient noise during movement is a result of the movement;
• and
• a cabin communication system for improving clarity of a voice spoken within an interior of said cabin, said cabin communication system comprising:
• a first microphone, positioned at a first location within the cabin, for receiving the spoken voice and the ambient noise and for converting the spoken voice into a first audio signal, the first audio signal having a first component corresponding to the ambient noise;
• a second microphone, positioned at a second location within the cabin, for receiving the spoken voice and the ambient noise and for converting the spoken voice into a second audio signal, the second audio signal having a second component corresponding to the ambient noise;
• a processor for summing the first and second audio signals to provide a resultant audio signal that is indicative of a detection location within the cabin relative to the first and second locations of said first and second microphones;
• a speech enhancement filter for filtering the resultant audio signal by removing the first and second components to provide a filtered audio signal;
• an echo cancellation system receiving the filtered audio signal and outputting an echo-cancelled audio signal;
• and
• a loudspeaker for converting the echo-cancelled audio signal into an output reproduced voice within the cabin including a third component indicative of the first and second audio signals,
• wherein said loudspeaker and said first and second microphones are acoustically coupled so that the output reproduced voice is fed back from said loudspeaker to be received by said first and second microphones and converted with the spoken voice into the first and second audio signals,
• wherein said echo cancellation system removes from the filtered audio signal any portion of the filtered audio signal corresponding to the third component, and
• wherein said speech enhancement filter comprises:
• a first filter element that smooths a spectrum of the resultant audio signal over larger windows at higher frequencies in accordance with a mel-scale to provide a smoothed audio signal;
• a second filter element that filters the smoothed audio signal with a causal Wiener filter to provide a Wiener filter result;
• and
• a third filter element that performs at one of temporal and frequency smoothing of the Wiener filter result to provide the filtered audio signal.