Abstract: The technology described in this document can be embodied in a method for processing an input signal that represents a signal of interest captured in the presence of noise to generate a de-noised estimate of the signal of interest. The method includes receiving an input signal representing a signal of interest captured in the presence of noise. The method also includes processing at least a portion of the input signal using a digital filter to generate a filtered signal, the digital filter configured to suppress at least a portion of spectrum of the noise. The method further includes processing the filtered signal using a first neural network to generate a de-noised estimate of the signal of interest, wherein the first neural network is trained to compensate for distortions introduced by the digital filter in the signal of interest.

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: In a general aspect, a system includes a controller configured to receive a first signal representative of a load on an engine and to generate a control parameter based on the first signal, one or more harmonic scaling elements, each configured to receive the control parameter and a different engine harmonic signal of a plurality of engine harmonic signals and to generate a scaled version of the 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, wherein at least some of the harmonic specific scaling factor values of the harmonic specific mapping element are mapped to control parameter values which are associated with a negative load on the engine, and an adjustable gain element for forming a scaled version of the received engine harmonic signal including applying the harmonic specific scaling factor to the received engine harmonic signal.

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: 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: 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 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.