Active noise cancellation aircraft headset system

A method of canceling noise within an earcup of an aircraft headset, comprising the steps of:

• transducing acoustic pressure within the earcup, which acoustic pressure includes both tonal noise generated by an engine of an aircraft and other broadband aircraft noise, to generate an analog error signal;
• providing the analog error signal to an analog filter which inverts it and generates an analog broadband noise cancellation signal;
• providing the analog error signal to an analog to digital converter which converts the analog error signal to a digital error signal;
• providing the digital error signal to a digital signal processor and, using an adaptive feedback filter, generating a digital tonal noise cancellation signal;
• providing the digital tonal noise cancellation signal to a digital to analog converter which converts the digital tonal noise cancellation signal to an analog tonal noise cancellation signal;
• summing the analog broadband noise cancellation signal and the analog tonal noise cancellation signal to generate a composite cancellation signal, and providing the composite noise cancellation signal to a speaker within the headset earcup, the speaker acoustically transducing the composite cancellation signal to reduce aircraft noise within the earcup.

A method of canceling noise within an earcup of an aircraft headset, comprising the steps of:

• transducing acoustic pressure within the earcup, which acoustic pressure includes both tonal noise generated by an engine of an aircraft and other broadband aircraft noise, to generate an analog error signal;
• inverting the analog error signal to generate an analog broadband noise cancellation signal;
• converting the analog error signal to a digital error signal;
• using a digital signal processor employing an adaptive feedback filter to generate a digital tonal noise cancellation signal based on the digital error signal;
• converting the digital tonal noise cancellation signal to an analog tonal noise cancellation signal;
• summing the analog broadband noise cancellation signal and the analog tonal noise cancellation signal to generate a composite cancellation signal;
• and
• acoustically transducing the composite cancellation signal within the headset earcup to reduce the tonal and broadband aircraft noise within the headset earcup.

An active noise cancellation aircraft headset system comprising:

• an earset including means for receiving and acoustically transducing an electronic composite noise cancellation signal, and means for transducing acoustic pressure within the earset to a corresponding analog error signal;
• an analog filter which receives the analog error signal and inverts it to generate an analog broadband noise cancellation signal;
• an analog to digital converter which receives the analog error signal and converts it to a digital error signal;
• a digital signal processor which receives the digital error signal and, using an adaptive feedback filter, generates a digital tonal noise cancellation signal;
• a digital to analog converter which converts the digital tonal noise cancellation signal to an analog tonal noise cancellation signal;
• summing means for receiving and summing the analog broadband noise cancellation signal and the analog tonal noise cancellation signal to generate the composite cancellation signal, the summing means providing the composite noise cancellation signal to the means for receiving and acoustically transducing the composite noise cancellation signal.