WO2019025774A1

WO2019025774A1 - Method and apparatus for enhancing vehicle sound and/or vibrations

Info

Publication number: WO2019025774A1
Application number: PCT/GB2018/052164
Authority: WO
Inventors: Paul KENNINGS; Marco Ballatore; Jonathan Layfield
Original assignee: Bentley Motors Limited
Priority date: 2017-08-03
Filing date: 2018-07-30
Publication date: 2019-02-07
Also published as: GB2565121A; GB201712477D0

Abstract

Sound and/or vibration in a vehicle (10) is enhanced by using at least one active powertrain mount (24, 26) to selectively generate vibrations in the vehicle body (12), at least some of which are audible to a person in a cabin of the vehicle. The method can be used to enhance the sound and feel of the vehicle powertrain. The active powertrain mounts typically include at least one active engine mount (24) but may also include at least one active transmission mount (26). The active mounts (24, 26) are controlled by an ECU to attenuate unwanted powertrain vibrations in the usual way whilst simultaneously generating vibrations in the vehicle body to augment desirable engine sounds/vibrations.

Description

Method and Apparatus for Enhancing Vehicle Sound and/or Vibrations

Technical Field of the Invention

The present invention relates to a method and apparatus for enhancing the sound and/or feel of a vehicle. The invention is directed in particular but not exclusively to a method and apparatus for enhancing the sound and/or feel of a vehicle powertrain.

Background to the Invention

Noise, vibration and harshness (NVH) engineering is an increasingly important aspect of vehicle development. One of the aims of NVH is to produce a pleasurable vibro-acoustic experience for vehicle occupants. A significant source of vibrations and noise in a vehicle is the powertrain, in particular the engine (or other type of power unit) and transmission. Vibrations from the powertrain are transmitted to the vehicle body through powertrain mounts, such as engine/power unit mounts and transmission mounts. It is known to use active vibration control (AVC) to attenuate undesirable powertrain vibrations. In one known arrangement, active powertrain mounts are used to at least partially cancel out undesirable powertrain vibrations by generating vibrations in anti-phase, that is to say vibrations of the same frequency but with a 180° phase difference. Each active mount has a force generating actuator capable of vibrating in a range of frequencies under the control of an Electronic Control Unit (ECU). In a typical system, an accelerometer or other vibration sensor is used to measure the body side vibrations and the ECU determines how much anti-phase vibration is required to cancel out the measured vibration in accordance with a predefined protocol. Whilst attenuating unwanted noise and vibrations in a vehicle cabin is an important aspect of NVH engineering, in some cases it can be advantageous to augment desirable sounds and vibrations. For many people the sound and feel produced by a vehicle's engine is an important part of the overall experience of driving. This is particularly so for high performance and luxury vehicles. However, the introduction of technologies designed to improve fuel efficiency and reduce emissions, as well as improved sound proofing and vibration control, affect the sound and feel of the engine as experienced inside the vehicle cabin in ways which are sometimes less desirable. For example, fuel management systems have been developed which vary the number of cylinders in operation in an internal combustion engine in dependence on the required power output. Such systems are sometimes referred to as "Cylinder De-Activation" (CDA). In vehicles having CDA, the vibrations and sound produced by the engine will vary in dependence on the number of cylinders in operation. Developments have also been made in vehicles powered by electric motors and hybrid vehicles incorporating a combustion engine in combination with an electric motor. Whilst such vehicles provide low emissions and high levels of efficiency, for many people the absence or variation in engine noise/vibration provides a less satisfying driving experience in comparison with a vehicle having a conventional internal combustion engine.

To overcome some of these issues, technologies have been developed to enhance or even replace the sound of a vehicle engine as experienced within a vehicle cabin. In some known arrangements, a sound system in the vehicle cabin is used to produce engine and powertrain sounds. This may involve playing samples of engine/powertrain sounds, for example. It is also known from WO2006/097188 Al to use an actuator mounted to a non-functional part of the vehicle body to generate acoustic vibrations which can be heard within the cabin to augment the sound of the actual engine/powertrain.

Whilst the known arrangements for augmenting sounds of a vehicle powertrain are effective, there are a number of drawbacks. Firstly, the known arrangements often require the use of additional, dedicated hardware components. This adds to the cost and increases the overall weight of the vehicle. Further, whilst the known arrangements enhance the sound of a vehicle powertrain, they do not enhance vibrotactile aspects of a vehicle occupant's experience.

There is a need therefore for an alternative method of enhancing the sound and/or vibrations of a vehicle, particularly as experienced inside a vehicle cabin, which overcomes, or at least mitigates, some or all of the drawbacks of the prior art methods. There is a need in particular for an alternative method of enhancing the sound and/or vibration in a vehicle which requires less dedicated hardware than the prior art methods.

There is also a need for an alternative method of enhancing the sound and/or vibration in a vehicle which enhances the vibrotactile as well as the acoustic experience of a vehicle occupant.

Further, there is a need for an alternative apparatus for enhancing the sound and/or vibration in a vehicle, especially as experienced inside a vehicle cabin, which overcomes, or at least mitigates, some or all of the drawbacks of the prior art apparatus.

There is a need in particular for an alternative apparatus for enhancing the sound and/or vibration in a vehicle which requires less dedicated hardware than the prior art apparatus.

There is also a need for an alternative apparatus for enhancing the sound and/or vibrations in a vehicle which enhances the vibrotactile as well as the acoustic experience of a vehicle occupant.

Summary of the Invention

According to a first aspect of the invention, there is provided a method of generating sound and/or vibrations in a vehicle, wherein the method comprises using at least one active powertrain mount to selectively generate vibrations in the vehicle.

At least some of the vibrations generated in the body may be audibly detectable by a person within the vehicle cabin.

According to a second aspect of the invention, there is provided a method of enhancing sound and/or vibration in a vehicle, wherein the method comprises using at least one active powertrain mount to selectively attenuate powertrain vibrations in at least one frequency by generating anti-phase vibrations and using said at least one active powertrain mount to selectively augment powertrain sound and/or vibrations in at least one other frequency by generating vibrations in the vehicle body. The method according to the first and second aspects of the invention can be used to generate vibrations in the vehicle body selected to enhance the sound and/or feel of the powertrain as experienced by a person within the vehicle cabin by attenuating undesirable powertrain sounds and/or vibrations whilst simultaneously augmenting desirable powertrain sounds and/or vibrations.

Where the powertrain has a power unit having a power unit shaft, the method may comprise selectively augmenting powertrain sound and/or vibrations by using the at least one active powertrain mount to generate vibrations in the vehicle body in at least one order relative to the speed of rotation of the power unit shaft (order addition). The at least one order to be augmented may be selected in dependence on the torque demand and/or speed of the power unit. Where the power unit is an internal combustion engine, the power output shaft may be a crankshaft. Where the power unit is an electric motor, the output shaft may be the motor shaft.

In an embodiment, the method can be carried out in a number of alternatively selectable modes of operation wherein the amplitude and/or the frequency of the vibrations generated in the vehicle body to augment powertrain sound and/or vibrations are varied in dependence on the mode.

In an embodiment the method is carried out in a number of enhancement modes and comprises applying a different sound and/or vibration enhancement protocol in each mode.

In an embodiment where a vehicle in which the method is implemented is selectively operable in a number of different performance modes, the method may comprise selecting the frequency/amplitude of the vibrations generated in the vehicle body to augment powertrain sound and/or vibrations in dependence on the performance mode selected. For example, in a vehicle which can be selectively operated in "comfort mode" intended for quiet and smooth running of the vehicle or a "sports mode" in which the vehicle is configured for higher performance, the method may be carried out when the comfort mode is selected with an emphasis on attenuating undesirable powertrain vibrations with only a limited amount of augmentation of desirable powertrain sounds and vibrations to produce a pleasant and satisfying experience for the occupants without being overly intrusive, whereas, when the sports mode is selected, the method may be carried out with a greater emphasis on augmenting desirable powertrain sounds and vibrations to produce sounds/vibrations within the cabin more reflective of a high performance vehicle with increased engine sound and a "throaty" exhaust. In an embodiment, the method comprises using the at least one active powertrain mount to augment powertrain sound and/or vibrations at selected frequencies by generating vibrations in a suitable phase relationship with the powertrain sound and/or vibrations. The generated vibrations will not usually be antiphase and may be in-phase with the powertrain sound and/or vibrations being augmented.

In an embodiment, the method comprises varying the amplitude of the vibrations generated in the vehicle body to augment powertrain sound and/or vibrations at selected frequencies in dependence on the torque demand and/or speed of a power unit forming part of the powertrain. Thus, the method may comprise increasing the level of augmentation of at least some desirable powertrain sounds/vibrations when the vehicle is accelerating hard or being driven at higher speeds.

In an embodiment, the method comprises varying the amplitude of the vibrations generated in the vehicle body powertrain sound and/or vibrations at selected frequencies in dependence on vehicle speed and/or acceleration and/or time of performance in a specific operating condition (e.g. idle, low speed cruise) or use, and/or external factors such as surrounding traffic conditions.

The at least one active powertrain mount may include at least one active power unit mount. The at least one active power unit mount may be an active engine mount. The at least one active powertrain mount may include at least one active transmission mount.

According to a third aspect of the invention, there is provided a method of enhancing sound and/or vibration in a vehicle, wherein the method comprises using at least one active powertrain mount to generate vibrations in the vehicle body in order to selectively attenuate undesirable powertrain vibrations and to selectively augment desirable powertrain sound and/or vibrations.

In accordance with a fourth aspect of the invention, there is provided apparatus for enhancing sound and/or vibrations in a vehicle, wherein the apparatus comprises at least one active powertrain mount for supporting the powertrain in a body of the vehicle, an electronic control unit for controlling operation of the at least one active engine mount, the ECU being configured to operate the at least one active powertrain mount to selectively attenuate powertrain vibrations in at least one frequency by generating anti-phase vibrations and using said at least one active powertrain mount to selectively augment powertrain sound and/or vibrations in at least one other frequency by generating vibrations in the vehicle body. The ECU may be configured to operate the at least one active powertrain mount to selectively generate vibrations in the vehicle body which give rise to sounds audible by a person within a cabin of the vehicle in use. In apparatus in accordance with the fourth aspect of the invention, the ECU may be configured to carry out the method in accordance with any of the first, second or third aspects of the invention.

In accordance with a fifth aspect of the invention, there is provided a vehicle comprising apparatus in accordance with the fourth aspect of the invention. In accordance with a sixth aspect of the invention, there is provided a vehicle configured to carry out the method according to any one of the first, second, or third aspects of the invention.

In accordance with a seventh aspect of the invention, there is provided an ECU or other programmable device for controlling operation of at least one active powertrain mount in a vehicle, the ECU or other programmable device being programmed to carry out the method according to any one of the first, second, third or further aspects of the invention. Detailed Description of the Invention

In order that the invention may be more clearly understood embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a perspective view of an embodiment of a vehicle in accordance with an aspect of the present invention, the vehicle being in the form of a motor car having a body, part of the body being ghosted to show the location of an engine and transmission;

Figure 2 is a side view of an Active Engine Mount (AEM) for use in the vehicle of Figure 1 and in the methods according to aspects of the invention;

Figure 3 is a cross sectional view through the AEM of Figure 2;

Figure 4 is function boundary diagram of an AEM system forming part of the vehicle of Figure 1 and which is configured to carry out the methods according to aspects of the invention. An embodiment of a motor vehicle 10 having an Active Engine Mount (AEM) system configured to carry out the method in accordance with aspects of the invention will be described with reference to the accompanying Figures.

The term "power unit" as used herein should be understood as encompassing an internal combustion engine, an electric motor, the combination of an electric motor and an internal combustion engine, and any other prime mover which provides motive power in a vehicle.

The term "power unit shaft" should be understood as encompassing any type rotary shaft in a vehicle power unit through which the motive force is transmitted and can encompass either or both of a crankshaft in an internal combustion engine and an electric motor shaft as the context requires.

The vehicle 10 is the form of a motor car having a body 12 which defines an engine compartment 14 and a passenger cabin 16 in which occupants of the vehicle are accommodated. The vehicle has a powertrain 18 comprising an engine 20 and a transmission 22. The engine and transmission are mounted to the vehicle body by two Active Engine Mounts (AEM) 24 located one on either side of the engine 20 and a transmission mount 26 supporting the transmission 22 on the body. The engine and transmission mounts 24, 26 will be referred to collectively as "powertrain mounts".

The AEMs 24 each have a force generating actuator which in a known manner is used to generate anti-phase vibrations to attenuate vibrations in the powertrain. The precise details of the construction of the AEMs 24 are not important to the present invention and any suitable known AEM of this type can be used. However, typically, an AEM consists of a passive mount (elastomeric or hydraulic), a force generating actuator and a structural vibration sensor. An example of a suitable hydraulic AEM 24 for use in the present invention is illustrated in Figures 2 and 3. The AEM 24 includes an engine side mounting member or leg 28 to which the engine is attached and a housing 30 which is attached the vehicle body. The engine side mounting member 28 and the housing 30 are inter-connected internally by means of an elastomeric mounting element 32 and a hydraulic damper 34. A force generating actuator in the form of an electromagnetic shaker 36 is operative between the housing 30 and the elastomeric element 32. An accelerometer 38 is attached to the mount housing 30 to measure body side vibrations. The AEMs 24 in this embodiment are capable of producing vibrations in the frequency range of 25 to 500Hz with up to 100N rms of force. The AEMs 24 form part of an AEM system of the vehicle as illustrated schematically in Figure 4.

The AEM system has an electronic control unit (ECU) 40 with an electrical power supply 42, which may be taken from a vehicle battery and/or alternator (not shown). The AEM system ECU has a Controller Area Network (CAN) interface 44 connected with the vehicle CAN bus 46 to enable data to be transferred between the AEM system ECU and other ECUs in the vehicle including an engine ECU 48. The data transferred to the AEM system ECU includes data relating to the speed 50 of the engine provided by a crankshaft sensor 52. The AEM system ECU includes memory for storing software 54 including algorithms and datasets and processing means for running the software. In use when the engine is running, vibrations are transmitted from the engine to the AEMs 24 via the engine side mounting members 28 in the form of forces acting in the axial direction of the mounts as indicated by the arrow 56 in Figure 4. These forces 56 are subject to passive dampening by the mounts 24 but in at least some frequencies are at least partially transmitted through the engine mounts to the vehicle body 12, giving rise to body side vibrations. The body side vibrations are detected by the accelerometer 38 of each AEM 24, which provides an input signal indicative of the body side vehicle vibrations detected to the AEM system ECU via an accelerometer interface 58. The AEM system ECU provides respective output signals to drive each of the actuators 36 of the AEMs 24 via an H-B ridge amplifier 60 to produce anti-phase vibrations 62 which oppose and at least partially cancel out undesirable engine vibrations 56 in accordance with a programmed algorithm and in dependence on the data from the relevant accelerometer. Each AEM 24 is independently controllable to cancel out vibrations on its side of the engine.

The use of AEMs 24 to attenuate powertrain and especially engine vibrations in a vehicle is well known and will not be discussed in great detail. However, such technology is often, but not exclusively, used in vehicles having internal combustion engines, including four stroke engines. Internal combustion engines typically produce vibrations whose frequencies are related to the rotational speed of the crankshaft. Vibrations which occur on each rotation of the crankshaft are referred to as first order vibrations. However, vibrations also occur at other orders of rotation, including for example vibrations resulting from the cylinders firing. The orders at which the most significant or troublesome vibrations occur is dependent on the engine configuration and firing order. For example, a W12 engine tends to produce 3^rd and 6^th order vibrations, a V8 engine 2^nd and 4^th order vibrations, and a V6 engine 1.5, and 3^rd order vibrations. AEMs 24 are typically used to attenuate particular orders of vibration depending on the engine and vehicle configuration such as those identified above. This is sometimes referred to as "order attenuation". Where a vehicle engine employs CDA, this gives rise to particular problems for vibration damping as the most problematic vibrations will tend to occur at different orders of rotation when the engine is operating at full power with all cylinders firing than when only some of the cylinders are firing. It is difficult with passive mounts to design a mount which is capable of attenuating engine vibrations in both full power mode and CDA running whilst at the same time meeting ride comfort requirements. The use of AEMs to attenuate vibrations is especially beneficial in vehicles having CDA where the AEMs can attenuate engine vibrations not only in full power mode but also over the whole CDA frequency range without overly compromising ride comfort.

In accordance with the present invention, in addition to attenuating engine and other powertrain vibrations, the AEMs 24 are used to induce vibrations in the body of the vehicle in order to further enhance the engine/powertrain sound and feel within the vehicle cabin by augmenting desirable powertrain sounds and/or vibrations. The AEM actuators are driven by the AEM system ECU in accordance with programmed algorithms to apply resultant forces 64 to the body 30 of the mount and hence to the vehicle body 12 giving rise to vibrations in the vehicle body in desired frequencies. At least some of the vibrations produced in the vehicle body by the AEMs will be audibly detectable by a person (human occupant) within the vehicle cabin. The system may be configured to augment certain frequency ranges of the engine. So for example, if the engine is not producing a desired level of sound at 250 Hz, the AEMs 24 can be activated to augment the sound in that area. The system may be configured to selectively augment certain engine orders which provide a better vibro-acoustic experience for the vehicle occupants. In this case, the vibrations produced by the AEMs 24 will be in a suitable phase relationship with the selected engine order vibrations that are being enhanced. This can be referred to as "order addition" as opposed to order attenuation. Typically, the vibrations produced by the AEMs 24 will be in-phase with the selected engine order vibrations that are being enhanced in order to boost these desirable frequencies. However, the system can, as an alternative or in addition, be configured to vibrate independently of any engine/powertrain vibrations to generate vibrations which give rise to desired sounds and/or which can be felt by occupants in the vehicle cabin. Either of the two AEMs 24 can be activated independently to enhance engine sounds or the two could be activated together, either in-phase or out of phase with each other. In an embodiment, the engine orders selected for augmentation and/or the amplitude of the vibrations generated in the vehicle body are varied in dependence on the vehicle speed and/or engine speed and/or the torque demand on the engine. In tests it has been found that at higher engine/vehicle speeds and torque, higher levels of order addition (number and amplitude) is beneficial whereas at lower speeds and/or lower torque, lower levels of enhancement are preferable as too much can be detrimental to the overall experience of the occupant. For example, for a given engine torque, the system may provide for higher levels of order attenuation at higher speeds than for the same level of torque at lower speeds. Data regarding torque loads may be taken from a torque map from the engine ECU 48 or from a transmission ECU and data relating to engine speed may be taken from a speed map from the engine ECU 48. The engine orders selected for enhancement and/or the amplitude of the vibrations generated in the body can also be varied in dependence on other factors including, but not limited to: vehicle acceleration, time of performance, specific operating conditions (e.g. idle, low speed cruise), and external factors such as surrounding traffic conditions.

The system can be configured to have two or more different sound enhancement modes and to apply a different enhancement protocol in each mode. For example, the system may have a comfort mode, a normal mode, a custom mode and a sport mode and be configured to produce different sound and feel enhancements in each mode. The different modes may be selectable by the vehicle operator and may be part of an overall vehicle performance management system including more variables, such as traffic, vehicle usage and road conditions. For example, the vehicle may have a "comfort mode" intended for quiet and smooth running of the vehicle and a "sports mode" in which the vehicle is configured for higher performance. In this case, when the comfort mode is selected the system applies a protocol in which the emphasis is on attenuating undesirable powertrain vibrations with only a limited amount of augmentation of desirable powertrain sounds and vibrations to produce a pleasant and satisfying experience for the occupants without being overly intrusive. However, when a sports mode is selected the system applies a different enhancement protocol with a greater emphasis on augmenting desirable powertrain sounds and vibrations to produce an increased engine sound and which could be arranged to simulate a "throaty" exhaust sound associated with high performance vehicles. Other modes may have suitable alternative enhancement protocols. It can be seen then that the system can be configured to employ a range sound/vibration enhancement protocols which may be selected automatically according different operating conditions of the vehicle and/or which may be selected according to user preference.

An advantage of using AEMs 24 to augment the sound of the engine in the vehicle cabin over the known systems is that it makes use of equipment already present in many vehicles and so does not require additional dedicated hardware. This reduces the overall cost and weight of the vehicle and avoids packaging issues which arise in trying to accommodate additional equipment. Further, AEMs 24 are generally capable of producing higher levels of force, up to in the region 100N rms in the present embodiment, than known dedicated engine sound enhancement actuators which typically produce around ION rms. Consequently, AEMs can produce higher magnitude vibrations in the vehicle body leading to a better vibro-acoustic experience. AEMs 24 are also better than the known dedicated engine sound enhancement actuators at producing low frequency vibrations, for example at a frequency which can be felt rather than heard. Further, the sounds/vibrations are generated close to the engine and so appear to a vehicle occupant to be coming from the correct source. Taken independently or in combination, these factors give rise to a much enhanced vibro-acoustic experience for vehicle occupants.

The transmission mount 26 may be a passive mount or it may be an active mount similar to the AEMs 24. Where the transmission mount 26 is an active mount, it can also be used as part of the power train sound/vibration enhancing system in combination with the AEMs 24. Typically, an active transmission mount 26 will be smaller than an AEM 24 producing less force, say 30-50N rms, over a different frequency range of say 35 to 500Hz and above. Use of one or more active transmission mounts 26 in addition to AEMs 24 increases the range of frequencies that can be enhanced and significantly increases the overall capability of the system. It will be appreciated that the various active powertrain mounts 24, 26 can be used singly or collectively in any combination in and out of phase to produce a desired effect. In some vehicle arrangements, the powertrain will be mounted using a combination of active and passive powertrain mounts. In this case, at least one or more of the active powertrain mounts is/are used to enhance the engine/powertrain sounds. Whilst the present invention has particular application in vehicle having an internal combustion engine, it could usefully be adopted on electric powered and hybrid vehicles. Electric motors produce vibrations at frequencies related to the rotational speed of the motor shaft and active powertrain mounts can be used to attenuate vibrations produced by the electric motor and/or transmission and to generate vibrations/sounds in the vehicle cabin in accordance with the present invention. In a hybrid vehicle, the engine sound enhancement arrangement described herein could be used to provide a smooth transition, in terms of sound and feel, from battery to engine operation, for example.

It should be appreciated that for use in the present invention the number and size of the active powertrain mounts, their frequency range and the force they produce can be varied as required for any given application and may be varied depending, for example, on the size and configuration of the engine and transmission.

The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.

Claims

1. A method of enhancing sound and/or vibration in a vehicle, wherein the method comprises using at least one active powertrain mount to selectively attenuate powertrain vibrations in at least one frequency by generating antiphase vibrations and using said at least one active powertrain mount to selectively augment powertrain sound and/or vibrations in at least one other frequency by generating vibrations in the vehicle body.

2. A method as claimed in claim 1, wherein the powertrain has a power unit having a power unit shaft and wherein selectively augmenting powertrain sound and/or vibrations comprises using the at least one active powertrain mount to generate vibrations in the vehicle body in at least one order relative to the speed of rotation of the power unit shaft.

3. A method as claimed in claim 2, wherein the method comprises selecting the at least one order to be augmented in dependence on the torque demand and/or speed of the power unit.

4. A method as claimed in any one of claims 1 to 3, wherein the method comprises providing a number of alternatively selectable modes of operation and varying the amplitude of the vibrations generated in the vehicle body to augment powertrain sound and/or vibrations at selected frequencies in dependence on the modes selected.

5. A method as claimed in any one of claims 1 to 4, wherein the method comprises using the at least one active powertrain mount to augment powertrain sound and/or vibrations at selected frequencies by generating vibrations in a suitable phase relationship with the powertrain sound and/or vibrations.

6. A method as claimed in any one of claims 1 to 5, wherein the method comprises varying the amplitude of the vibrations generated in the vehicle body to augment powertrain sound and/or vibrations at selected frequencies in dependence on the torque demand and/or speed of a power unit forming part of the powertrain. A method as claimed in any one of claims 1 to 6, wherein the method comprises varying the amplitude of the vibrations generated in the vehicle body powertrain sound and/or vibrations at selected frequencies in dependence on vehicle speed and/or acceleration and/or time of performance in a specific operating condition (e.g. idle, low speed cruise) or use, and/or external factors such as surrounding traffic conditions.

A method as claimed in any one of claims 1 to 6, wherein the at least one powertrain mount includes at least one power unit mount.

A method as claimed in any one of claims 1 to 7, wherein the at least one powertrain mount includes at least one transmission mount.

Apparatus for enhancing sound and/or vibrations in a vehicle, wherein the apparatus comprises at least one active powertrain mount for supporting a powertrain in a body of the vehicle, an ECU for controlling operation of the at least one active engine mount, the ECU being configured to operate the at least one active powertrain mount to selectively attenuate powertrain vibrations in at least one frequency by generating anti-phase vibrations and using said at least one active powertrain mount to selectively augment powertrain sound and/or vibrations in at least one other frequency by generating vibrations in the vehicle body.

Apparatus as claimed in claim 10, wherein the ECU is configured to carry out the method of any one of claims 1 to 9.

A vehicle configured to carry out the method of any one of claims 1 to 9.

A vehicle comprising the apparatus of claim 10 or claim 11.

An ECU for controlling operation of at least one active powertrain mount in a vehicle, the ECU being programmed to carry out the method of any one of claims 1 to 9.