Sample-based engine noise synthesis using a harmonic synchronous overlap-and-add method (original) (raw)

An efficient technique for modeling and synthesis of automotive engine sounds

IEEE Transactions on Industrial Electronics, 2001

This paper presents a new method for modeling and synthesis of automotive engine sounds using a deterministic-stochastic signal decomposition approach. First, the deterministic component is extracted using a synchronous discrete Fourier transform method and this is subtracted out from the original signal. Next, the (residual) stochastic component is modeled (and synthesized) using a new multipulse excited time-series modeling technique. The effectiveness of the proposed methodology is demonstrated using recorded data sets of actual engine sounds. The results of both numerical and subjective assessment tests are presented.

ADAPTING THE OVERLAP-ADD METHOD TO THE SYNTHESIS OF NOISE

2002

Spectral synthesis techniques often use the OverLap-Add method. But in the case of noise synthesis, both experiments and theory show that this method introduces intensity fluctuations which imply audible artifacts. We propose here new methods to avoid these variations. The first one consists in multiplying the resulting signal by another weighting window to compensate dynamic fluctuations. The second one defines a new OLA weighting window. The third one concerns only noises synthesized with sinusoidal components and uses time-shifting to cancel artifacts.

Analysis by synthesis of engine sounds for the design of dynamic auditory feedback of electric vehicles

Acta acustica, 2023

In traditional combustion engine vehicles, the sound of the engine plays an important role in enhancing the driver's experience of the vehicle's dynamics, and contributes to both comfort and safety. However, with the development of quieter electric vehicles, drivers no longer receive this important auditory feedback, and this can lead to a less satisfying acoustic environment in the vehicle cabin. To address this issue, sonification strategies have been developed for electric vehicles to provide similar auditory feedback to the driver, but feedback from users has suggested that the sounds produced by these strategies do not blend seamlessly with the other sounds in the vehicle cabin. This study focuses on identifying the key acoustic parameters that create a sense of cohesion between the synthetic sounds and the vehicle's natural soundscape, based on the characteristics of traditional combustion engine vehicles. Through analyzing the time and frequency of the noises produced by combustion engine vehicles, the presence of micro-modulations in both frequency and amplitude was identified, as well as resonances caused by the transfer of sound between the engine and the cabin. These parameters were incorporated into a synthesis model for the sonification of electric vehicle dynamics, based on the Shepard-Risset illusion. A perceptual test was conducted, and the results showed that the inclusion of resonances in the synthesized sounds significantly enhanced their naturalness, while micro-modulations had no significant impact.

Spectral-Based Analysis and Synthesis of Audio Signals

Technologies and Applications, 2007

This chapter reviews audio signal processing techniques related to sound generation via additive synthesis. Particular focus will be put on sinusoidal modeling. Each processing stage involved in obtaining a sinusoidal representation for audio signals is described. Then, synthesis techniques that allow reconstructing an audio signal based on a given parametric representation are presented. Finally, some audio applications where sinusoidal modeling is employed are briefly discussed.

Auralization of Accelerating Passenger Cars Using Spectral Modeling Synthesis

While the technique of auralization has been in use for quite some time in architectural acoustics, the application to environmental noise has been discovered only recently. With road traffic noise being the dominant noise source in most countries, particular interest lies in the synthesis of realistic pass-by sounds. This article describes an auralizator for pass-bys of accelerating passenger cars. The key element is a synthesizer that simulates the acoustical emission of different vehicles, driving on different surfaces, under different operating conditions. Audio signals for the emitted tire noise, as well as the propulsion noise are generated using spectral modeling synthesis, which gives complete control of the signal characteristics. The sound of propulsion is synthesized as a function of instantaneous engine speed, engine load and emission angle, whereas the sound of tires is created in dependence of vehicle speed and emission angle. The sound propagation is simulated by applying a series of time-variant digital filters. To obtain the corresponding steering parameters of the synthesizer, controlled experiments were carried out. The tire noise parameters were determined from coast-by measurements of passenger cars with idling engines. To obtain the propulsion noise parameters, measurements at different engine speeds, engine loads and emission angles were performed using a chassis dynamometer. The article shows how, from the measured data, the synthesizer parameters are calculated using audio signal processing.

Real-Time Generation of Sound from Parameters of Additive Synthesis

1999

We describe a system for generating sounds in real-time. The input t o the system is a flow of parameter values. These values control t he frequency and amplitude of a bank of oscillators. The time between two sets of parameter values in the flow is much larger than the time between two samples of the resulting sound. The sound generation system must compute the instantaneous value of each oscillator and then sum the results. The main problem is then to get sufficient performance out of the computation of each instantaneous oscillator value. Sine tables were ruled o ut because they either r equire interpolation (which is slow) or massive amounts of memory (essentially one table for each frequency). A w ell-known formula e xists for incrementally computing the samples of an oscillator, g iven any frequency and any amplitude, with only one floating-point multiplication and one floating-point addition per sample. This formula has two major problems. The first is that the parameters are...

An Efficient Time–Frequency Method for Synthesizing Noisy Sounds With Short Transients and Narrow Spectral Components

IEEE Transactions on Audio, Speech, and Language Processing, 2000

The inverse fast Fourier transform (IFFT) method is a time-frequency technique which was proposed to alleviate the complexity of the additive sound synthesis method in real-time applications. However, its application is limited by its inherent tradeoff between time and frequency resolutions, which are determined by the number of frequencies used for time-frequency processing. In a previous work, the authors proposed a frequency-refining technique for overcoming this frequency limitation, permitting achieving any time and frequency resolution using a small number of frequencies. In this correspondence we extend this work, by proposing a time-refining technique which permits overcoming the time resolution limitation for a given number of frequencies. Additionally, we propose an alternative to the frequency-refining technique proposed in our previous work, which requires about half the computations. The combination of these two results permits achieving any time and frequency resolution for any given number of frequencies. Using this property, we find the number of frequencies which minimizes the overall complexity. We do so considering two different application scenarios (i.e., offline sound design and online real-time synthesis). This results in a major complexity reduction in comparison with the design proposed in our previous work.

Physically informed car engine sound synthesis for virtual and augmented environments

The richness of crossmodal feedback in car driving makes it an en- gaging, complex, yet “natural” activity. Audition plays an impor- tant role, as the engine sound, perceived in the cabin, conveys rel- evant cues about the vehicle motion. In this paper, we introduce a procedural and physically informed model for synthetic combustion engine sound, as an effective, flexible and computationally efficient alternative to sample-based and analysis/resynthesis approaches. The sound model, currently being developed as Max/MSP exter- nal, has been integrated in GeneCars, a driving simulator environ- ment for industrial sound design, and SkAT Studio, a demonstration framework for the rapid creation of audio processing workflows.

On the Use of Time-Frequency Reassignment in Additive Sound Modeling

Advances in Engineering Software, 2000

We introduce the use of the method of reassignment in sound modeling to produce a sharper, more robust additive representation. The Reassigned Bandwidth- Enhanced Additive Model follows ridges in a time- frequency analysis to construct partials having both si- nusoidal and noise characteristics. This model yields greater resolution in time and frequency than is possible using conventional additive techniques, and

REAL-TIME ADDITIVE SYNTHESIS OF SOUND BY TAKING ADVANTAGE OF PSYCHOACOUSTICS

In this paper we present an original technique designed in order to speed up additive synthesis. This technique consists in taking into account psychoacoustic phenomena (thresholds of hearing and masking) in order to ignore the inaudible partials during the synthesis process, thus saving a lot of computation time. Our algorithm relies on a specific data structure called "skip list" and has proven to be very efficient in practice. As a consequence, we are now able to synthesize an impressive number of spectral sounds in real time, without overloading the processor.