Abstract: A remote microphone system for a vehicle may include at least one physical microphone arranged within a vehicle cabin configured to generate an error signal at a virtual microphone location within the vehicle, a database configured to maintain a look up table of premeasured seat positions and associated transfer functions, and a processor. The processor may be configured to receive a seat position indicative of a seat location within the vehicle, and apply a transfer function associated with the premeasured position to a primary noise signal of the at least one physical microphone to generate the error signal.

Abstract: A noise cancellation system for a vehicle audio system may include at least one input sensor arranged on an engine of a vehicle configured to provide an input signal indicative of acceleration or vibration detected at the engine and a processor. The processor may be programmed to receive a reference signal, apply at least one order tracking to reference signal, generate an error signal based on an output signal, and apply at least one other order tracking filter to the error signal to provide engine order cancelation of the input signal.

Abstract: A remote microphone system for a vehicle may include at least one physical microphone arranged within a vehicle cabin configured to generate an error signal at a virtual microphone location within the vehicle, a database configured to maintain a look up table of premeasured seat positions and associated transfer functions, and a processor. The processor may be configured to receive a seat position indicative of a seat location within the vehicle, and apply a transfer function associated with the premeasured position to a primary noise signal of the at least one physical microphone to generate the error signal.

Abstract: A propagation delay identification system for active noise cancelation for a vehicle audio system may include at least one sensor configured to transmit sensor data indicative of acceleration data, hammer data and microphone data, at least one output sensor configured to transmit an impulse response, and a processor. The processor may be programmed to receive the sensor data and pulse function, identify a propagation path delay between the microphone data and a cross-correlation between the acceleration data and hammer data, and generate a source pulse function. The processor further identify a secondary path delay based on an arrival time of peak energy of a convolution of the impulse response and filtered pulse function, and apply a binary limiter to a reference signal in response to the secondary path delay exceeding the propagation path delay to reduce boosting of an audio signal based on coherent reference and error signals.

Abstract: A propagation delay identification system for active noise cancelation for a vehicle audio system may include at least one sensor configured to transmit sensor data indicative of acceleration data, hammer data and microphone data, at least one output sensor configured to transmit an impulse response, and a processor. The processor may be programmed to receive the sensor data and pulse function, identify a propagation path delay between the microphone data and a cross-correlation between the acceleration data and hammer data, and generate a source pulse function. The processor further identify a secondary path delay based on an arrival time of peak energy of a convolution of the impulse response and filtered pulse function, and apply a binary limiter to a reference signal in response to the secondary path delay exceeding the propagation path delay to reduce boosting of an audio signal based on coherent reference and error signals.

Abstract: A vehicle exhaust system component includes an exhaust tube defining an exhaust gas flow path, a side branch tuning tube connected to the exhaust tube at an interface, and a porous structure associated with the exhaust tube to reduce noise generated at the interface. In one example, the porous structure comprises a perforated orifice in the exhaust tube. In another example, the porous structure comprises a mesh screen or mesh sleeve.

Abstract: A coherence based dynamic stability control system for a vehicle audio system may include at least one output sensor configured to transmit an output signal including a noise cancellation signal and an undesired noise signal, and at least one input sensor configured to transmit an input signal indicative of an acceleration of a vehicle. A processor may be programmed to control a transducer to output the noise cancellation signal based on at least one parameter, receive the input signal and the output signal, determine a coherence between the input signal and the output signal. The processor may be further programmed to determine whether the coherence exceeds a predefined coherence threshold, adjust the at least one parameter to generate an adjusted parameter and control the transducer to output an updated noise cancellation signal based on the parameter in response to the coherence failing to exceed the predefined coherence threshold.

Abstract: A vehicle exhaust system component includes an exhaust tube defining an exhaust gas flow path, a side branch tuning tube connected to the exhaust tube at an interface, and a porous structure associated with the exhaust tube to reduce noise generated at the interface. In one example, the porous structure comprises a perforated orifice in the exhaust tube. In another example, the porous structure comprises a mesh screen or mesh sleeve.