A drive motor and a retarder in a powertrain meet a condition that a harmonic order of the drive motor is the same as a quantity of gear teeth of an input shaft gear in the retarder such that a frequency of an electromagnetic noise harmonic generated by the drive motor is the same as a frequency of a noise harmonic generated by the retarder. When the drive motor and the retarder are coupled using a connection structure, a phase of the electromagnetic noise harmonic generated by the drive motor differs from a phase of the noise harmonic generated by the retarder by a set angle.

To reduce engine noise in the cabin of an aircraft a plurality of error microphones is deployed at predetermined locations within the cabin to produce error microphone response signals associated with the engine noise in the cabin. Engine vibration inputs are obtained from sensors coupled to the aircraft engines. A processor is used to code the error microphone response signals into an encoded modal response in the cabin through a coding matrix. A processor is used to apply an adaptive filter to determine a plurality of modal signals needed to cancel the encoded modal response in the cabin. A processor is used to decode the modal signals into speaker input signals through a decoding matrix. Speaker input signals are then sent to a plurality of speakers to reduce the engine noise in the cabin.

A simulation test system and method for vehicle road noise cancellation (RNC) are provided in one or more embodiments of the present disclosure. The simulation test system may include a vehicle RNC simulation system and a power amplifier. The vehicle RNC simulation system is configured to simulate an RNC system in a vehicle environment. The power amplifier is configured to execute an RNC algorithm and may perform data communication with the vehicle RNC simulation system. The vehicle RNC simulation system transmits acceleration data representing an acceleration signal and microphone data representing a microphone signal to the power amplifier as inputs to the RNC algorithm in the power amplifier. Moreover, the vehicle RNC simulation system may receive speaker data representing a speaker signal from the power amplifier. The vehicle RNC simulation system includes a secondary path simulation model and a signal flow simulation model.

A vehicle includes an engine and/or powertrain producing noise that is audible in a passenger compartment of the vehicle when the engine and/or powertrain is running. An active noise control arrangement includes a first loudspeaker disposed within a passenger compartment of the vehicle. A digital signal processor receives audio data and transmits an audio signal to the first loudspeaker dependent upon the audio data. A microphone is disposed within the passenger compartment and converts the sound from the first loudspeaker and the noise within the passenger compartment into a microphone signal. The microphone signal is transmitted to the digital signal processor, and the digital signal processor modifies the audio signal such that the audio signal attenuates the noise in the passenger compartment. A vehicle processor transmits a simulated noise signal to a second loudspeaker for use in testing effectiveness of the active noise control arrangement in attenuating noise when the engine and/or powertrain is not running and not producing noise.

A simulation test system and method for vehicle road noise cancellation (RNC) are provided in one or more embodiments of the present disclosure. The simulation test system may include a vehicle RNC simulation system and a power amplifier. The vehicle RNC simulation system is configured to simulate an RNC system in a vehicle environment. The power amplifier is configured to execute an RNC algorithm and may perform data communication with the vehicle RNC simulation system. The vehicle RNC simulation system transmits acceleration data representing an acceleration signal and microphone data representing a microphone signal to the power amplifier as inputs to the RNC algorithm in the power amplifier. Moreover, the vehicle RNC simulation system may receive speaker data representing a speaker signal from the power amplifier. The vehicle RNC simulation system includes a secondary path simulation model and a signal flow simulation model.

An active noise reduction device includes: a reference signal input terminal that receives a reference signal from a reference signal source attached to an automobile; a simulated vibration transfer characteristics filter unit that generates a second signal by correcting, using simulated vibration transfer characteristics, a first signal for outputting, from a loudspeaker attached to the automobile, a sound different from a canceling sound, the simulated vibration transfer characteristics simulating vibration transfer characteristics from the loudspeaker to the reference signal source; a first subtracter that outputs a corrected reference signal obtained by subtracting the second signal generated, from the reference signal received by the reference signal input terminal; and an adaptive filter unit that applies an adaptive filter to the corrected reference signal outputted from the first subtracter to generate a canceling signal to be used to output the canceling sound.

A system for evaluating a noise management module of a vehicle includes a controller programmed to filter speaker signals from the noise management module using an auralization model to produce auralized sound signals that create a spatial effect to simulate sound in the vehicle at a predetermined position within the vehicle that is different than the positions corresponding to microphones used by the noise management module.

A system for evaluating a noise management module of a vehicle includes a controller programmed to filter speaker signals from the noise management module using an auralization model to produce auralized sound signals that create a spatial effect to simulate sound in the vehicle at a predetermined position within the vehicle that is different than the positions corresponding to microphones used by the noise management module.

A vehicle includes an engine and/or powertrain producing noise that is audible in a passenger compartment of the vehicle when the engine and/or powertrain is running. An active noise control arrangement includes a first loudspeaker disposed within a passenger compartment of the vehicle. A digital signal processor receives audio data and transmits an audio signal to the first loudspeaker dependent upon the audio data. A microphone is disposed within the passenger compartment and converts the sound from the first loudspeaker and the noise within the passenger compartment into a microphone signal. The microphone signal is transmitted to the digital signal processor, and the digital signal processor modifies the audio signal such that the audio signal attenuates the noise in the passenger compartment. A vehicle processor transmits a simulated noise signal to a second loudspeaker for use in testing effectiveness of the active noise control arrangement in attenuating noise when the engine and/or powertrain is not running and not producing noise.

A vehicle includes an engine and/or powertrain producing noise that is audible in a passenger compartment of the vehicle when the engine and/or powertrain is running. An active noise control arrangement includes a first loudspeaker disposed within a passenger compartment of the vehicle. A digital signal processor receives audio data and transmits an audio signal to the first loudspeaker dependent upon the audio data. A microphone is disposed within the passenger compartment and converts the sound from the first loudspeaker and the noise within the passenger compartment into a microphone signal. The microphone signal is transmitted to the digital signal processor, and the digital signal processor modifies the audio signal such that the audio signal attenuates the noise in the passenger compartment. A vehicle processor transmits a simulated noise signal to a second loudspeaker for use in testing effectiveness of the active noise control arrangement in attenuating noise when the engine and/or powertrain is not running and not producing noise.