# Interface Design for Responsible Remote Driving: A Study on Technological Mediation
## 4 Interface Design Analysis
### Hearing: Audio Feedback
Similarly, interacting properly with law enforcement officers during stops or accidents also appears to be necessary, while the possibility of verbally interacting with other road users might also prove effective in some safety-critical situations. To cope with these requirements, audio interfaces would then involve comfortable, high-quality headphones or earphones transmitting sounds caught by microphones installed inside and outside the vehicle aimed at enhancing the sense of immersion in the driving task. Communication with people inside (and, perhaps, outside) the vehicle could be made possible through microphones transmitting ROs' voice to vehicle speakers [51; 52]. Some specificities of the mediation process require attention. First, it is to be noted that the amplification of ROs' hearing is associated with displacement: ROs are located in an environment that is different from the one producing the sounds they hear. At the same time, noise is necessarily present where ROs' control stations are located, particularly if ROs can communicate verbally with people at the vehicle's location while working side by side with other ROs in facilities hosting multiple control stations. Noise isolation, then, becomes essential to allow ROs to focus on critical auditory cues while minimizing external distractions--apart, of course, for environmental safety-critical sounds such as fire alarms. The right amount of isolation is important to achieve safety at both locations involved in the mediation of driving. Moreover, an interesting reduction in the mediation of hearing concerns the possibility of locating the spatial source of a sound [41]. While in the unmediated settings of regular driving, it is often possible to realize whether a sound comes from behind, ahead, aside, or inside the vehicle, this spatial characterization of sounds becomes lost in the mediation unless dedicated technologies are deployed to retrieve it. For instance, the implementation of 3D audio systems would improve spatial awareness by simulating sound sources from different directions. This would potentially create more immersive soundscapes, enabling ROs to accurately locate auditory cues. A similar solution might importantly support responsible decision-making in situations in which ROs need to figure out where emergency or law enforcement vehicles signaling their incoming arrival through sirens are about to appear or need to locate the exact position of a horn sound [16]. In addition, immersive soundscapes mimicking the auditory conditions of regular driving might contribute to making RD more realistic, thus counteracting the troublesome impression of an overly gamified experience. Finally, audio feedback offers avenues to amplify the kinds of information perceivable by hearing through a translation process analogous to the one already discussed with reference to VR and sight. Indeed, many current vehicles already implement sound alarms and warnings aimed at supporting responsible driving when vision is variously impaired. For example, proximity or lane departure alarms warn distracted drivers when a collision is imminent or the vehicle is drifting, while speed alarms make sure drivers do not drive too fast without noticing. In all these instances, predominantly visual information is translated into sound cues to prompt responsible behavior. Given the overreliance on visual inputs and related risks of cognitive overload, integrating similar audio technologies in RD HMIs seems important to put ROs in best possible conditions to exercise responsibility. Indeed, hearing--the receptivity of which cannot be easily impeded--lends itself better than eyesight to be relied upon in cases of emergency. Moreover, sound-based feedback might be extremely useful during complex maneuvers where depths and widths are difficult to evaluate correctly due to the reductions of visual HMIs and would bring much needed clarity without burdening sight.