Developing method describing impression of unknown sounds through non-acoustic event - For a sound design of electric vehicle

It is important, however, to know the factors that make sounds to recall EVs particularly to design the warning sounds for EVs to ensure awareness of them. However, most of people have not had experience to see, listen to, or drive electric vehicles (EVs), then the sound of EVs are unknown for most of people. To understand these factors, we developed a method to know an impression of unknown sounds through non-acoustic events related to the impression of running EVs, in this study those were the impression of road environments or the driving impression. We assumed that if the impression of the non-acoustic events were highly related to running EVs, the sounds that had similar impression could be evaluated to harmonize with EVs. At the first stage of the presenting method, we conducted a large scale social survey to collect enough number of words that correspond with the non-acoustic events. The collected answers were divided some clusters which represent the non-acoustic events by by hierarchical cluster analysis using the mutual occurrence frequency between two words. Then the impression of the landscapes that were evoked by each word cluster was examined through the SD-method subjective evaluation experiment. As the result, we described the impression of the sounds that would potentially harmonize with driving EVs.