The subjective dimensions of sound quality of standard production electric vehicles

Sound quality for internal combustion engine vehicles is well documented in literature, and the underlying dimensions that govern the sound character have been identified. However, little is known about the dimensions that govern sound quality and character of electric vehicles. Electric vehicle sound signatures are characterized by significant high frequency content caused by the tonal harmonics that are emitted from the electric drive systems. Currently, the quiet sound emissions of electric vehicles at low speeds pose a safety risk to pedestrians and cyclists. Legislation in several countries stipulate that a warning sound should be added to the inherent signature sound of these vehicles to enhance the audio-detectability of these vehicles. Furthermore, consumer perceptions of the interior sound quality point to an unsatisfactory and bland sound character. Could the electric motor sound be modified in such a way that it not only satisfies legislation, but also improves consumer satisfaction? The effects of various sound modifiers are investigated, by means of jury testing, in order to asses the influence on juror satisfaction. The results revealed that enhanced sounds were preferred above standard production electric vehicle sounds. It was concluded that electric vehicle sound quality is complex and the multi-dimensional sound space should be considered as a whole, rather than mere individual subjective semantics.