Zero-Emission Vehicles Sonification Strategy Based on Shepard-Risset Glissando

International audienceIn this paper we present a sonification strategy developed for electric vehicles aiming to synthetize a new engine sound to enhance the driver's dynamic perception of his vehicle. We chose to mimic the internal combustion engine (ICE) noise by informing the driver through pitch variations. However, ICE noise pitch variations are correlated to the engine's rotations per minute (RPM) and its dynamics is covered within a limited vehicle speed range. In order to inform the driver with a significant pitch variation throughout the full vehicle speed range, we based our sonification strategy on the Shepard-Risset glissando. These illusory infinite ascending/descending sounds enable to represent accelerations with significant pitch variations for an unlimited range of speeds. In a way, we stay within the metaphor of ICE noise with unheard gearshifts. We tested this sonification strategy in a perceptual test in a driving simulator and showed that the mapping of this acoustical feedback affects the drivers' perception of vehicle dynamics

Car door closure sounds: characterization of perceptual properties through analysis-synthesis approach

International audienceThe aim of this study is to identify perceptually pertinent parameters for the evaluation of car door closure sounds. For this purpose, perceptual properties of recorded sounds were first evaluated by sensory metrology. Then, an analysis-synthesis approach was chosen in order to identify perceptually pertinent signal parameters. The analysis part of this process first consisted in decomposing the sound in several independent impact sources using the Empirical Modal Decomposition method. Each impact is then modeled by a set of gains and damping factors in each critical band (ERB). These parameters were further used to synthesize sounds related to various aspects of the door closure sound with a real-time tool. This approach allowed for the generation of realistic, synthesized car door closure sounds that preserve perceptual properties with a reduced number of signal parameters. Listening tests finally allowed for the observation of the influence of the main signal parameters on the perceptual properties of such action-related impact sounds

How does interior car noise alter driver's perception of motion? Multisensory integration in speed perception

International audienceAcoustic feedback inside a car is composed of different sources, which give information on the drivers actions and the dynamic state of the car. This acoustic feedback influences the drivers perception of movement in a multisensory integration. The development of electric motorizations brings new balance between noise sources inside the car, due to the loss of engine sound that is present in traditional internal combustion engine cars. To study the influence of this modified noise source balance on driving, we focused on speed perception. A car simulator was used for this purpose. 24 participants were asked to accelerate up to a given target speed, while the speedometer was hidden. We studied the speed they actually reached with three acoustic feedbacks (engine, electric motor, no sound), in two visual conditions (night and day). We found out that acoustic feedback can alter the drivers speed perception

Motor noise influence on acceleration perception in a dynamic driving simulator

International audienceAutomotive acoustic is living a revolution due to new power train introduction. Interior car noise is now designed, offering fresh perspective in terms of sound ambiance. For 4-cylinders car, interior car noise can sound more expressive in order to increase sensation by motor organic modification. Our goal is indeed to conceive interior car sound which is well fitted with car dynamic. This experience studies the relation between acoustic perception and motion perception in a dynamic driving simulator. We test motor noise influence on the car perceived power during an acceleration by modifying motor noise loudness and brigthness. Subjects sit in passenger side three different accelerations are reproduced in the driving simulator. We show that car perceived power increased with loudness whereas brightness doesnt have an impact

Perceptual Analysis of Vibrating Bars Synthsized with a Physical Model

cote interne IRCAM: Roussarie98a/National audiencePeople have a remarkable capacity to quickly and efficiently understand certain aspects of the current state of the world based on the behavior of sound-producing objects, even those outside the field of vision. Early work on the subjective representation of sound events consisted of correlating abstract perceptual parameters (timbre) with parameters stemming from spectral analyses (attack time, spectral center of gravity, etc.) by means of multidimensional scaling (MDS) analysis (1). These analytic spectro-temporal parameters were based on a simplified representation of the acoustic signal, which may not account completely for the complexity of human perception. The principal objective of the work presented here was to attempt to find a direct link, if possible, between the physical nature of the vibrating object that produces sound events and the perception of that object by listeners. We thus hypothesized that the perceptual system should be sensitive to aspects of the acoustic environment that have biological importance for the listener or that have acquired a particular value through auditory experience with sounds of the daily environment. Such an approach has been already used in a discrimination paradigm (2), but without simulating sounds with a physical model, thus impeding the establishment of a direct link between perceptual dimensions and source properties

Perceptual analyses of action-related impact sounds

International audienceAmong environmental sounds, we have chosen to study a class of action-related impact sounds: automobile door closure sounds. We propose to describe these sounds using a model composed of perceptual properties. The development of the perceptual model was derived from the evaluation of many door closure sounds measured under controlled laboratory listening conditions. However, listening to such sounds normally occurs within a natural context, which probably modifies their perception. We therefore need to study differences between the real situation and the laboratory situation by following standard practices in order to specify the precise listening conditions and observe the influence of previous learning, expectations, action-perception interactions, and attention given to sounds. Our process consists in doing in situ experiments that are compared with specific laboratory experiments in order to isolate certain influential, context dependent components

The psychomechanics of simple sound sources: Material properties of impacted bars

cote interne IRCAM: McAdams04eNone / NoneNational audienceNon