An apparatus for synthesizing an engine sound according to an embodiment of the present invention comprises: a memory for storing a plurality of explosion sound samples corresponding to a plurality of cylinders included in a cylinder module, respectively; a sound output unit; and a processor for calculating explosion periods of the plurality of cylinders, and overlapping the plurality of samples stored according to the calculated explosion periods on explosion noises of corresponding cylinders, respectively, to output a synthesized virtual engine sound through the sound output unit.

An apparatus for controlling engine noise reflecting engine vibration and driving conditions includes a sound generator that generates reinforcement noise in order to reinforce non-linear engine noise. The apparatus includes a vibration sensor measuring engine vibration as a noise source of the engine, a signal processing controller receiving the signal of the vibration sensor in real time and controlling the sound generator so that the engine noise may maintain linearity, and an amplifier receiving and then amplifying a control signal of the signal processing controller to transfer the amplified control signal to the sound generator.

Methods and systems for reducing a pressure wave are provided. In an exemplary embodiment, a motor vehicle comprises a cabin and a receiver positioned to detect an input pressure wave within the cabin and produce an input signal. A fan with a blade having a variable pitch is positioned within the vehicle where the fan is audible within the cabin. A processor is in communication with the receiver and the fan, where the processor is configured to receive the input signal and determine an input frequency and an input phase. The processor is further configured to instruct the fan to control a pitch of the blade to produce a cancellation pressure wave with a cancellation frequency that is about the same as the input frequency and a cancellation phase that is about 180° out of phase with the input phase.

An ASC apparatus, which actively generates a sound effect inside a cabin of a vehicle provided with an internal combustion engine and an electric motor as driving sources, includes: a reference signal generating unit which generates a harmonic reference signal based on a vehicle-speed-corresponding frequency, being a frequency based on a vehicle speed, by referring to waveform data; a driver seat speaker which outputs a sound including the sound effect; and a signal processing unit which generates a control signal that forms the sound effect by multiplying the reference signal by a sound effect gain related to the reference signal, and outputs the control signal to the driver seat speaker. The signal processing unit sets the sound effect gain based on a state of charge of a storage battery.

In at least one embodiment, a system for providing a frequency dependent dynamic leakage for noise cancellation is provided. The system includes a noise cancellation controller and a current limiter. The noise cancellation controller is programmed to perform noise cancellation in a vehicle based on a limited input signal. The current limiter is programmed to receive a reference signal from one of an accelerometer or a loudspeaker and to convert the reference signal from a time domain and into a frequency domain to limit the reference signal. The current limiter is further programmed to generate the limited input signal in response to limiting the reference signal.

A method of canceling road noise includes: receiving a first signal from an acceleration sensor disposed at a vehicle and a second signal from a microphone disposed at the vehicle; monitoring, based on the first and second signals, whether an abnormal event has occurred; determining, based on a result from monitoring whether the abnormal event has occurred, a plurality of parameter values for performing adaptive filtering; and performing, based on the determined parameter values, adaptive filtering to generating an output signal for noise canceling.

A system for generating silent zones at a listening position comprises a first loudspeaker disposed at a first position and configured to radiate sound that corresponds to a sound signal. A first microphone picks up noise radiated by a noise source to the listening position and generates a first microphone signal. A second loudspeaker disposed at a second position that radiates sound. A second microphone that generates a second microphone signal. A third microphone disposed at a third position that generates a third microphone signal. An active noise cancellation (ANC) controller that receives the third microphone signal and at least one of the first and second microphone signals and that provides a loudspeaker input signal. A distance between the third position and the first position equals a distance between the third position and the second position such that the first, second and third microphones form corners of an isosceles triangle.

A method of controlling a tone of an electric vehicle (EV) includes calculating order components from vibration signals of a rotating motor of the EV, extracting an N.sup.th order component having a determination coefficient R.sup.2 which represents linearity with respect to an output torque of the motor and is greater than or equal to a predetermined value, converting an RPM of the motor into a frequency and calculating an order frequency, arranging the order components by applying a vibration level of the N.sup.th order component to a level of the order frequency to be output and setting an EV mode tone, and in a deceleration of the EV, determining a deceleration condition and applying the vibration level of the N.sup.th order component to level control of the order frequency.

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.

Various technologies described herein pertain to active noise cancellation in the interior of a vehicle. In exemplary embodiments, a microphone mounted on the vehicle outputs an audio signal indicative of noise emitted by a noise source. A computing system of the vehicle determines a position of the noise source based upon sensor signals output by sensors mounted on the vehicle. The computing system further determines a position of a passenger in the vehicle based upon a sensor mounted inside the vehicle. The computing system generates a complementary signal that is configured to attenuate the noise based upon the audio signal, the position of the noise source, and the position of the passenger. The complementary signal is then output by way of a speaker in the interior of the vehicle.