The sound generated by electric propulsion systems differs compared to the prevalent sound generated by combustion engines. By exposing listeners to various sound situations, the manufacturer can start understanding which direction to take to achieve compelling battery electric vehicle trucks from a sound perspective.The main objective of this study is to understand what underlying aspects decide the experience and perception of heavy vehicle–related sounds in the context of electrified propulsion. Using a thematic analysis of data collected at a listening experiment conducted in 2020, factors affecting the perception of novel sounds generated by a first-generation electric truck are investigated. A hypothesis is that the experience of driving or being a passenger in electric trucks will affect the rating and response differently compared to listeners not yet experienced with this sound. The results show that the combination of individual preference and experience, hearing function, acoustic content, time variation, signal stability, load-dependent feedback, and situation-equivalent sounds affect the outcome. The assessment and rating of quality and acceptance did not differ between battery electric truck experienced listeners and first-time listeners in general. The only driving condition clearly breaking this pattern was the auxiliary brake condition, which, besides being significantly higher rated by novel listeners, also stood out as the highest-rated and most positively commented driving operation overall. In conclusion, several combined factors affect the assessment of electric truck sounds. Three identified aspects are removing disturbing sounds, making the sound environment smooth and silent, and providing clear functional feedback. Memory of the contextual experience is a key factor when assessing sounds from driving operations. The expected difference between listeners with and without experience with electric truck sounds will be minor unless there is exceptionally high sound quality.

In future confined industrial contexts (hubs), highly automated vehicles and human operators may work in shared spaces and collaborate on joint tasks. This will probably generate a demand for new user interfaces between humans and machines that need to be designed to facilitate high levels of safety and efficiency as well as a positive user experience (UX). The present work investigates the potential of using a combination of voice interaction (VI) and visual augmented reality (AR) to support collaboration between automated vehicles and humans manually operating a machine. A concept using VI and AR for a loading scenario in a logistic center was created and evaluated using a VR headset to provide an immersive experience. A user study with 18 forklift drivers was conducted. Our study shows that the concept generated high scores in terms of usability and UX, which indicates a promising potential to use VI and AR to facilitate interaction between human machine operators and unmanned highly automated vehicles when performing collaborative tasks. Our study also implies a need to explore the design and implementation of more complex and social VI for users in logistic centers.

The present study investigated the potential of using gestures to guide and control unmanned automated heavy vehicles in underground mine contexts, as well as the effects of adding external human-machine interfaces (eHMIs) to provide feedback during the gesture interaction. A study with 12 professional operators was conducted in a simulated mine environment, utilizing a Wizard of Oz methodology. The subjects used gestures to guide and control a heavy vehicle in three different scenarios in the mine, and different aspects of the user experience (UX) were assessed. The results support the notion that there is high potential in using gestures when operators stand in close proximity to the vehicles. Moreover, the results suggest that eHMI solutions can enhance the operator’s acceptance and feelings of safety. The selected gestures seemed appropriate for the investigated scenarios, which should be valuable insights for practitioners intending to develop and implement gesture interaction for similar applications.

The present work-in-progress paper describes the development ofnovel user interface concepts that allow human operators to collaborate with self-driving heavy vehicles in a mining context. Conceptdevelopment was performed within a user-centered design processcontaining three main steps. First, a study was performed to identifyinteraction points between heavy vehicle drivers and other humanoperators in mines. Second, potential interaction technologies wereinvestigated. Finally, suggestions for interaction models were designed and implemented in 3D animated movies. The concepts weredesigned to support human operators performing loading tasks together with self-driving vehicles and utilize voice interaction and anaugmented reality head-up-display to facilitate the interaction. Inaddition to the mining context, similar concepts were developed tosupport forklift drivers performing loading tasks in logistic centers.In the next step of this project, the suggested interaction modelswill be evaluated with mine workers and forklift drivers.

Motion sickness may be a factor detrimental to the experience of self-driving cars. This study investigates whether auditory displays can support in lowering passengers' feeling of motion sickness by allowing them to anticipate upcoming manoeuvres. Twenty participants took part in the study and rode on a specially designed test track with and without auditory display while performing a reading task. The display provided information about upcoming car manoeuvres, which were identified as being motion sickness inducing and the sounds were designed to resemble the actual sound of the manoeuvres taking place. Sounds representing acceleration, deceleration and left and right turns were played slightly in advance of the upcoming manoeuvre. Participants rated their motion sickness at regular intervals during the ride as well as before and after the ride. The results showed that illness ratings in the auditory display condition were statistically lower significantly compared to the condition without sound. The sounds were also judged as intuitive and helpful by the users who reported willingness to use them when riding autonomous cars in the future, especially while reading or working. These results have implications for the interaction design of self-driving cars and can guide future auditory display research. 

A main challenge to the successful wide scale introduction of self-driving vehicles is users' trust in automation technology. This study's primary aim was to investigate whether auditory displays can enhance users' trust when they ride in self-driving cars. Twenty-eight subjects participated in an experiment utilising a virtual reality simulation. All subjects rode in a virtual vehicle with and without an auditory display. The display contained signals that provided information about the intentions of the car, as well as other road users that the car focused on. Participants' responses were collected during and after the rides. The results suggest that auditory displays can be useful to improve users' trust. Furthermore, the designed auditory display received high scores in terms of user acceptance. These results have implications for the interaction design of self-driving cars and can guide future auditory display research.

Vehicles powered by electric motors can be very quiet at low speeds, which can lead to new road safety issues. The European Parliament has decided that quiet vehicles should be equipped with an Acoustic Vehicle Alerting System (AVAS). The main purpose of the studies presented in this paper was to investigate whether future requirements could affect people's acceptance of electric vehicles (EVs). The strategy in the first study was to create an immersive, simulated auditory environment where people could experience the sounds of future traffic situations. The second study was conducted with a car on a test track. The results suggest that the requirements are not likely to have a major negative effect on people's experience of EVs or willingness to buy an EV. However, the sounds can have a certain negative effect on emotional response and acceptance, which should be considered by manufacturers. The results of the test track study indicate that unprotected road users may appreciate the function of an AVAS sound. The work did not reveal any large differences between AVAS sounds. But in the simulated environment, sounds designed to resemble an internal combustion engine tended to receive more positive scores. © 2018 Copyright is held by the owner/author(s).

While traffic signals, signs, and road markings provide explicit guidelines for those operating in and around the roadways, some decisions, such as determinations of "who will go first," are made by implicit negotiations between road users. In such situations, pedestrians are today often dependent on cues in drivers' behavior such as eye contact, postures, and gestures. With the introduction of more automated functions and the transfer of control from the driver to the vehicle, pedestrians cannot rely on such non-verbal cues anymore. To study how the interaction between pedestrians and automated vehicles (AVs) might look like in the future, and how this might be affected if AVs were to communicate their intent to pedestrians, we designed an external vehicle interface called automated vehicle interaction principle (AVIP) that communicates vehicles' mode and intent to pedestrians. The interaction was explored in two experiments using a Wizard of Oz approach to simulate automated driving. The first experiment was carried out at a zebra crossing and involved nine pedestrians. While it focused mainly on assessing the usability of the interface, it also revealed initial indications related to pedestrians' emotions and perceived safety when encountering an AV with/without the interface. The second experiment was carried out in a parking lot and involved 24 pedestrians, which enabled a more detailed assessment of pedestrians' perceived safety when encountering an AV, both with and without the interface. For comparison purposes, these pedestrians also encountered a conventional vehicle. After a short training course, the interface was deemed easy for the pedestrians to interpret. The pedestrians stated that they felt significantly less safe when they encountered the AV without the interface, compared to the conventional vehicle and the AV with the interface. This suggests that the interface could contribute to a positive experience and improved perceived safety in pedestrian encounters with AVs - something that might be important for general acceptance of AVs. As such, this topic should be further investigated in future studies involving a larger sample and more dynamic conditions.