Abstract: A method that is accomplished in a vehicle engine harmonic modification system. A non-zero target engine harmonic signal that is representative of a target engine harmonic sound level in the vehicle cabin is provided. The target engine harmonic signal is used in an operation of the engine harmonic modification system so as to modify the level of engine harmonic sound in the vehicle cabin, to bring the engine harmonic sound level in the vehicle cabin closer to the target engine harmonic sound level.

Abstract: A method to produce a dynamic sound stage for engine harmonic enhancement (EHE). Dynamic refers to the ability to position the sound stage at different positions as the engine operates at various RPMs and load. In order to control the sound stage width, a phase difference can be introduced between a first audio channel (e.g., a left audio channel) and second audio channel (e.g., a right audio channel). In the most general case, the phase difference can be introduced per harmonic per RPM. In this approach, the phase difference can be adjusted such that a vehicle occupant will perceive each harmonic signal to have a particular width. This width can be adjusted independently per RPM regions by tuning the per harmonic phase difference.

Abstract: A method to produce a dynamic sound stage for engine harmonic enhancement (EHE). Dynamic refers to the ability to position the sound stage at different positions as the engine operates at various RPMs and load. In order to control the sound stage width, a phase difference can be introduced between a first audio channel (e.g., a left audio channel) and second audio channel (e.g., a right audio channel). In the most general case, the phase difference can be introduced per harmonic per RPM. In this approach, the phase difference can be adjusted such that a vehicle occupant will perceive each harmonic signal to have a particular width. This width can be adjusted independently per RPM regions by tuning the per harmonic phase difference.

Abstract: A method that is accomplished in a vehicle engine harmonic modification system. A non-zero target engine harmonic signal that is representative of a target engine harmonic sound level in the vehicle cabin is provided. The target engine harmonic signal is used in an operation of the engine harmonic modification system so as to modify the level of engine harmonic sound in the vehicle cabin, to bring the engine harmonic sound level in the vehicle cabin closer to the target engine harmonic sound level.

Abstract: In a vehicle equipped with a vehicle sound system, determining a virtual fixed gear ratio; determining a virtual RPM based on the virtual fixed gear ratio; generating a set of harmonic signals based on the virtual RPM, the harmonic signals being sine-wave signals proportional to harmonics of the virtual RPM; processing the harmonic signals to produce a set of processed harmonic signals; and in the vehicle sound system, transducing the processed harmonic signals to acoustic energy thereby to produce an engine sound within a passenger cabin of the vehicle.

Abstract: An engine harmonic enhancement system. The EHE system uses multiple parameters, such as engine load, gear, number of cylinders operating, and transmission ratio, to determine EHE gains to determine EHE gain. The EHE system determines a separate EHE gain for each harmonic.

Abstract: In a vehicle equipped with a vehicle sound system, determining a virtual fixed gear ratio; determining a virtual RPM based on the virtual fixed gear ratio; generating a set of harmonic signals based on the virtual RPM, the harmonic signals being sine-wave signals proportional to harmonics of the virtual RPM; processing the harmonic signals to produce a set of processed harmonic signals; and in the vehicle sound system, transducing the processed harmonic signals to acoustic energy thereby to produce an engine sound within a passenger cabin of the vehicle.

Abstract: A method includes providing a fundamental frequency corresponding to the RPM of an engine of a vehicle; determining a plurality of harmonics of the fundamental frequency; and determining a target shape of the plurality of harmonics. The target shape includes, for each of the harmonics of the plurality of the harmonics, a gain value as a function of the RPM of the engine. The method also includes determining an accelerator pedal position (APP) based gain that includes a gain value as a function of an accelerator pedal position; and determining a speed based gain that includes a gain value as a function of a difference between a set maximum speed and a measured vehicle speed. The method further includes combining the plurality of harmonics, the target shape of the plurality of harmonics, the APP based gain, and the speed based gain to produce a set of engine harmonic enhancement signals.

Abstract: An engine harmonic enhancement system. The EHE system uses multiple parameters, such as engine load, gear, number of cylinders operating, and transmission ratio, to determine EHE gains to determine EHE gain. The EHE system determines a separate EHE gain for each harmonic.

Abstract: In a general aspect, a system includes circuitry for providing an engine harmonic scaling module and a summer. The engine harmonic scaling module is configured to receive a torque signal and a throttle signal, process the torque signal to generate a calibrated torque value, process the throttle signal to generate a throttle percentage value, determine a control parameter based on an examination of the calibrated torque value and the throttle percentage value, determine, based on the control parameter, a harmonic-specific scaling factor for each of one or more engine harmonic signals of a plurality of engine harmonic signals, and apply the corresponding harmonic-specific scaling factor to each of the one or more engine harmonic signals to generate corresponding scaled engine harmonic signals. The summer is configured to generate, from the scaled engine harmonic signals, a combined engine harmonic signal.

Abstract: A method to produce a dynamic sound stage for engine harmonic enhancement (EHE). Dynamic refers to the ability to position the sound stage at different positions as the engine operates at various RPMs and load. In order to control the sound stage width, a phase difference can be introduced between a first audio channel (e.g., a left audio channel) and second audio channel (e.g., a right audio channel). In the most general case, the phase difference can be introduced per harmonic per RPM. In this approach, the phase difference can be adjusted such that a vehicle occupant will perceive each harmonic signal to have a particular width. This width can be adjusted independently per RPM regions by tuning the per harmonic phase difference.

Abstract: A system includes a controller for receiving first and second signals representative of a load on an engine, and generating based on the signals. Harmonic scaling elements generate a scaled version of a received engine harmonic signal. Each harmonic scaling element includes a harmonic specific mapping element for mapping the control parameter to a harmonic specific scaling factor. Some of the harmonic specific scaling factor values of the harmonic specific mapping element are mapped to control parameter values associated with a negative load on the engine, and some are mapped to control parameter values associated with a positive load on the engine. The control parameter values associated with the negative load are derived from the first signal, and control parameter values associated with the positive load are derived from the second signal. An adjustable gain element applies the harmonic specific scaling factor to the received engine harmonic signal.

Abstract: A method includes providing a fundamental frequency corresponding to the RPM of an engine of a vehicle; determining a plurality of harmonics of the fundamental frequency; and determining a target shape of the plurality of harmonics. The target shape includes, for each of the harmonics of the plurality of the harmonics, a gain value as a function of the RPM of the engine. The method also includes determining an accelerator pedal position (APP) based gain that includes a gain value as a function of an accelerator pedal position; and determining a speed based gain that includes a gain value as a function of a difference between a set maximum speed and a measured vehicle speed. The method further includes combining the plurality of harmonics, the target shape of the plurality of harmonics, the APP based gain, and the speed based gain to produce a set of engine harmonic enhancement signals.

Abstract: In a vehicle equipped with a vehicle sound system, determining a virtual fixed gear ratio; determining a virtual RPM based on the virtual fixed gear ratio; generating a set of harmonic signals based on the virtual RPM, the harmonic signals being sine-wave signals proportional to harmonics of the virtual RPM; processing the harmonic signals to produce a set of processed harmonic signals; and in the vehicle sound system, transducing the processed harmonic signals to acoustic energy thereby to produce an engine sound within a passenger cabin of the vehicle.

Abstract: An RPM signal representing a current RPM of a vehicle engine is received. An instant magnitude and an instant phase are determined for each of N harmonics of a target engine sound based on the RPM signal. The instant magnitude and the instant phase are each smoothed to generate a smoothed harmonic magnitude and a smoothed harmonic phase for each of the N harmonics. A magnitude perturbation signal and a phase perturbation signal are generated for each of the N harmonics. An individual harmonic signal is also generated for each of the N harmonics based, at least in part, on the smoothed harmonic magnitude, the magnitude perturbation signal, the smoothed harmonic phase, and the phase perturbation signal. The individual harmonic signals are summed to generate an engine harmonic enhancement signal, and the engine harmonic enhancement signal is transduced to acoustic energy.

Abstract: A method includes performing a harmonic decomposition on a target engine sound, thereby to extract each of N harmonics of the target engine sound over an RPM range; and out of the extracted harmonics, extracting phase and shape information for each of the N harmonics over the RPM range for reproducing the target engine sound. The method also includes configuring an engine harmonic enhancement (EHE) system to utilize the extracted phase and shape information to generate an engine harmonic enhancement signal, he(t), to be added on top of a baseline engine sound.

Abstract: A method includes performing a harmonic decomposition on a target engine sound, thereby to extract each of N harmonics of the target engine sound over an RPM range; and out of the extracted harmonics, extracting phase and shape information for each of the N harmonics over the RPM range for reproducing the target engine sound. The method also includes configuring an engine harmonic enhancement (EHE) system to utilize the extracted phase and shape information to generate an engine harmonic enhancement signal, he(t), to be added on top of a baseline engine sound.

Abstract: In a general aspect, a system includes a controller which generates a control parameter based on a signal representative of a load on an engine. One or more engine harmonic signals are generated based on the control parameter.

Abstract: A vehicle engine harmonic enhancement system. A method for operating the system includes providing a first engine harmonic enhancement audio signal and equalizing the first engine harmonic enhancement audio signal separately for each of the plurality of loudspeakers to provide individually equalized loudspeaker engine harmonic enhancement audio signals. A vehicle audio system includes a plurality of loudspeakers, an entertainment audio system, and an engine harmonic enhancement system. A method includes equalizing an entertainment audio signal to provide an equalized entertainment audio signal; providing an engine harmonic enhancement audio signal; equalizing the engine harmonic enhancement audio signal separately from the entertainment audio signal to provide an equalized engine harmonic enhancement audio signal; and combining the equalized entertainment audio signal with the equalized engine harmonic enhancement audio signal.

Abstract: An engine harmonic enhancement system. The EHE system uses multiple parameters, such as engine load, gear, number of cylinders operating, and transmission ratio, to determine EHE gains to determine EHE gain. The EHE system determines a separate EHE gain for each harmonic.