The increasing number of electric and hybrid vehicles in urban areas has shown to be beneficial in reducing both air and noise pollution. However, the lack of sound when driving at low speed has negatively affected the pedestrian safety since many rely on the vehicle sound for orientation. Regulatory bodies have therefore introduced minimum sound requirements for all silent vehicles, which has resulted in a key challenge for car manufacturers to develop external warning signature sounds. The objective of this project has been to study how these signals should sound in order to fit the image of electric and hybrid vehicles and minimize noise and annoyance. To complete the study, five sound concepts with different characteristics and rhythms were developed using the concept generation process. In order to gain subjective impressions of the sounds, three measurement methods were utilized. The first listening test was performed to eliminate the possibility that the sound samples would be perceived variously loud in the upcoming tests. The second listening test was performed to gain information on how suitable the signals are for electric and hybrid vehicles, and the third listening test was conducted to obtain information on how much annoyance the signals contributed with. A reference signal representing an internal combustion engine was included in the tests as well. The results of the measurement methods showed that the sound samples with long tone sequences were more preferred than those with short tone sequences, and that the artificial approach was more popular than the sound of an internal combustion engine vehicle. It was also established that additional tests need to be performed in order to confirm that these results are valid. It was suggested that field tests should be conducted and that new sound concepts should be developed based on the results of these tests.

Aujourd'hui, l'identité sonore des marques concerne principalement les musiques associées aux publicités ou diffusées sur les points de vente, ainsi que des éléments de communication comme la voix ou les jingles. Dans cette thèse, nous nous intéressons au design sonore des produits et équipements comme vecteur de l'identité de marque. Nous proposons une méthodologie de design sonore identitaire permettant de traduire les valeurs d'une marque en termes sonores, et de véhiculer l'identité sonore ainsi définie sur une série d'objets caractéristiques de la marque. A partir d'une analyse d'un grand nombre d'études sur la perception des sons, nous avons établi un lexique sonore de 35 termes adapté à la description des différentes caractéristiques du son. Nous proposons d'utiliser ce lexique ainsi que différents outils de communication pour traduire les valeurs identitaires d'une marque en termes sonores compréhensibles par tous les acteurs du projet en design sonore. Nous proposons également une méthode d'analyse fonctionnelle permettant de spécifier les contraintes techniques liées à la nature ou à la fonction de l'objet choisi pour véhiculer l'identité. Cette méthode repose sur une expérience d'indexation sonore, inspirée de l'analyse sensorielle. La méthodologie proposée a été appliquée au design de l'identité sonore de la marque SNCF véhiculée à travers différentes sources (alarmes, composteurs, tableau d'affichage,...). Ces travaux ont permis de construire et de tester des méthodologies et outils facilitant la communication dans le design sonore, et ont montré que l'identité des marques pouvait s'exprimer à travers la conception des sons de leurs produits et équipements. / Brands are today looking for new ways to convey their identity. Currently, brands sound identity is mostly based on music for ads or for selling places, and communication elements like voice or jingles. In this thesis, we focus on products sound design as a way to convey brand identity. Is it possible to take into account brand values in the writing of the requirements for a sound designer? For a given object, what are the relevant design features to consider in order to communicate a desired identity? In our works, we propose a sound design methodology for the translation of brand values into sound attributes, and for conveying the resulting sound identity through a series of products. Based on the analysis of several studies on sound verbal description, we elicited a sound lexicon of 35 words adapted to the description of sound properties. We propose to use this lexicon along with two communication tools, moodboards and a “sound design deck”, to translate brand identity into words easily understandable by both experts and non-experts. We also propose a methodology for linking the physical constraints of the objects to design to words of the lexicon. This method is based on a sound indexing experiment, inspired from sensory analysis. The methodology we propose is applied to the design of SNCF sound identity through different elements (alarms, validating machines, split-flap displays…). The originality of this work resides in its interdisciplinarity combining different approaches such as marketing, design, sensory analysis and auditory perception. This work proposes both methodologies and tools that facilitate communication in sound design, and shows that it is possible to convey brand identity through products sound design.