Increasing global awareness of the benefits of electromobility has brought about the need for new concepts in terms of the acoustic design of future vehicle generations. This includes both the creative design process and the development of suitable methods for the subjective evaluation of target sounds. The main difference between e-car sound surveys and those carried out on familiar sound categories is the potential consumer's lack of experience with electric vehicles. Thus, the consumer has no, or very unspecific, expectations in this regard. Several studies have shown that many subjects have to construct their personal frame of reference for evaluation within the listening experiment. However, this is possibly at odds with experience-based expectations relating to sounds of conventional combustion engines. The result is a conflict of objectives between the traditional and the modern, familiarity and strangeness, and not least between driving freedom and ecological awareness. In this context, the authenticity of the sound and the subjective interpretability of the sound information also appear as moderator variables. Moreover, associations with other vehicle categories, for example, streetcars, also influence the perceived sound quality. Within this contribution, these factors will be expounded and their influence on the evaluation of interior noise discussed.

The evaluation of vehicle interior sounds in a listening study is always based on multiple sensory interactions. In a driving simulator several visual and somatosensory stimuli are presented to the test subjects in addition to the pure driving sounds. These multisensory stimuli are processed consciously and unconsciously by the human brain. Thus attention processes and also the evaluation behavior change in comparison to monosensory acoustical experiments. In the automotive industry electric powered vehicles currently are a hot topic. These vehicles have a very quiet noise behavior compared to vehicles with combustion engines. So the question arises how driving sounds comprise to the subjective evaluation of a vehicle's acceleration. Do we associate loud driving sounds with strong acceleration? Which part takes the spectral structure of a sound? In a comparative listening study different vehicle interior sounds and different accelerations were evaluated in two different driving simulators. Based on the results from the study the influence of driving sounds on the subjective evaluation of longitudinal acceleration is discussed.

One fundamental requirement for a widespread use of electric powered vehicles is a high degree of social acceptance of alternative drive concepts. As part of this, perception and evaluation of comfort and quality in a vehicle become increasingly important. The customers' judgment on these factors is strongly influenced by the noise and vibration behavior of the vehicle and always is passed in the context of multiple sensory impressions which are processed in the human brain consciously and unconsciously. The interaction mechanisms of sensory perception are highly complex and raise several scientific questions. During the past years, valuable insights about the interaction of visual and auditory perception have been obtained and there are also a number of theories about the auditory-tactile interaction. In contrast, the connection between auditory and proprioceptive perception remains largely unexplored. This paper deals with the question how acceleration forces influence human auditory perception. In order to make evident possible crossmodal effects, a listening experiment was conducted in different kinds of driving simulators. The results of this study will be presented and discussed.

Laboratory listening studies are typically limited in the number of people who can participate because of the effort that is involved in setting up and carrying out the experiment for each participant. This effort has significantly increased since the start of the COVID-19 pandemic due to the heightened public health requirements for in-person studies. This increase in effort and the resulting limit on the number of participants can be avoided by implementing the listening study as an online interface, where participants can then run the experiment from the comfort of their home and anyone who has access to a computer and headphones is able to participate. Such an approach supports the goal of involving the general public, who are the ultimate target audience for the research outcome. This contribution presents the preliminary results of an online listening study assessing the perceived annoyance due to impact sounds in residential buildings. The interface was previously validated and presented (Internoise 2021) with limited data. Since then, the survey has been published online for worldwide access. The results are discussed in relation to the results of previous laboratory studies.

To support efforts of introducing an impact sound requirement into the National Building Code of Canada (NBCC), the National Research Council of Canada has initiated a long-term research project. In cooperation with the Hochschule Duesseldorf in Germany and Kangwon National University in Korea, several listening tests were performed to investigate the annoyance due to impact sound as it is perceived by building occupants, and how this annoyance relates to the results of standardized laboratory measurements. In this contribution, the different listening test setups will be described and compared. Tests were performed in the laboratory using loudspeakers, headphones, and also with a Virtual Reality headset. In addition, an online listening test was launched to expand the reach of such studies to the general population. The results will be summarized and discussed regarding appropriate rating methods. The goal of these studies is to gain a better understanding of the relevant factors that affect the perceived annoyance, such as the impact source type and the dominant frequency range, but also how the test environment influences the results.