Cold temperature negatively impacts the performance of liquid crystal displays (LCDs). In cars, this leads to slow response times and reduced image quality. We investigated how the perception of video distortions on LCD screens was affected by cold temperatures down to −43°C. The stimuli were generated using digital filters simulating how different time constants of the LCD crystals would affect the video distortions. Seven levels of time constants were applied to four variations of video content. Simulated videos were shown in a psychophysical experiment involving 20 test persons. Judgements of video clarity and acceptance were conducted by magnitude estimation and category scales. The two different judgements based on magnitude estimations and psychophysical scales gave similar results. Clarity and acceptance correlated. A modified Arrhenius function was employed to model time constants based on temperature, showing unacceptable quality of the LCD-display below –20°C. The traffic scenes were perceived as clear and acceptable with time constants ranging from 0 and 50 ms. The critical range between 50 to 100 ms corresponded to a temperature range between –20°C to –30°C, beyond which clarity and acceptance decreased. Perception of an unacceptable video quality was found for distortions at time constants between 100 to 500 ms.

This study investigates how different camera perspectives presented in digital rear-view mirrors in vehicles, also known as Camera Monitor Systems, impact drivers’ distance judgment and decision-making in dynamic driving scenarios. The study examines (1) the effects of field of view and (2) camera height on drivers' ability to judge distances to rearward vehicles and to select safe gaps in potentially hazardous situations. A controlled lab-based video experiment was conducted, involving 27 participants who performed distance estimations and last safe gap selections using a simulated side-view mirror display. Participants viewed prerecorded driving scenarios with varying combinations of field of view (40°, 76°, 112°) and camera heights (1 meter, 2.3 meter). No significant effects were found for camera height, but wider field of views led to more accurate distance estimations. However, the use of a wider field of view also increased the risk of potentially dangerous overestimations of distance, as evidenced by the last safe gap results. This suggests that a wider field of view leads to the selection of smaller and potentially risky gaps. Conversely, narrow field of views resulted in underestimations of distance, potentially leading to overly cautious and less efficient driving decisions. These findings inform Camera Monitor Systems design guidelines on how to improve driver perception and road safety, to reduce accidents from vehicle distance misjudgments.

Remote control technology for machines and robots has experienced significant advancement in many domains where visual information delivery is essential. Safety management at airports is one field that benefits from remote control systems, enabling operators to scan the airstrip for obstacles and debris. Depth perception and proper view position are critical in remote control systems, where operators need to accurately perceive 3D coordinates and maintain an appropriate perspective for performing tasks from a distance. This Demo paper presents a laboratory platform for an experimental study on human interaction with remote control systems using visual interfaces for inspection tasks to enhance airport safety management. The platform can evaluate the user experience of interfaces provided by First Person View, Third Person View, and Augmentation technologies. This platform enables exploration through controlled experiments and by user tests. These provide an avenue for assessing how these interfaces may affect human performance, depth perception, and user experience when conducting inspection tasks remotely. The findings will shed light on the strengths and limitations of each interface type, offering insights into their potential applications in various domains such as industrial inspection, surveillance, and remote exploration.

A well-known drawback with LCD-displays in cold is a slow pixel response leading to poor picture quality. Low temperatures can constitute a hazard in viewing important displays in cars. Perceptual experiments with 20 test-persons were conducted to find clear and acceptable ranges on screens simulating distortions in low temperatures. The results showed perception over clear and acceptable image quality was impaired beyond -20°C for the LCD-screen in the experiments.

Digital technology offers multimodal presentation of information, that can be used for translating foreign languages or for alleviating hearing impairment or deafness communication problems. Today, there exists various aids that can be used for speech-to text translations, but there are some challenges with these. One potential solution for this is to make use of a combination of Augmented Reality (AR) and speech-to-text systems, where speech is converted into text that is then presented in AR-glasses. In AR, one crucial problem is the legibility and readability of text under different environmental conditions. Different types of AR glasses have different ergonomic characteristics, which implies that certain glasses might be more suitable for such a system than others. In this investigation, two different AR-glasses were evaluated based on among other things their optical, visual, and ergonomic characteristics. User tests were conducted to evaluate the legibility and readability of text under different environmental contexts. The results indicate that legibility and readability are affected by factors such as ambient illuminance, background properties and how the text is presented with respect to polarity, opacity, size, and number of lines. The characteristics of the glasses impacts the user experience, but which glasses that is preferred depends on the individual.

Human echolocation describes how people, often blind, use reflected sounds to obtain information abouttheir ambient world. Using auditory models for three perceptual variables, loudness, pitch and one aspectof timbre, namely sharpness, we determined how these variables can make people detect objects byecholocation. We used acoustic recordings and the resulting perceptual data from a previous study withstationary situations, as input to our analysis. One part of the analysis was on the physical room acousticsof the sounds, i.e. sound pressure level, autocorrelation and spectral centroid. In a second part we usedauditory models to analyze echolocation resulting from the perceptual variables loudness, pitch andsharpness. Based on these results, a third part was the calculation of psychophysical thresholds with anon-parametric method for detecting a reflecting object with constant physical size for distance, loud-ness, pitch and sharpness. Difference thresholds were calculated for the psychophysical variables, sincea 2-Alternative-Forced-Choice Paradigm had originally been used. We determined (1) detection thresh-olds based on repetition pitch, loudness and sharpness varied and their dependency on room acousticsand type of sound stimuli. We found (2) that repetition pitch was useful for detection at shorter distancesand was determined from the peaks in the temporal profile of the autocorrelation function, (3) loudnessat shorter distances provides echolocation information, (4) at longer distances, timbre aspects, such assharpness, might be used to detect objects. (5) It is suggested that blind persons may detect objects atlower values for loudness, pitch strength and sharpness and at further distances than sighted persons.We also discuss the auditory model approach. Autocorrelation was assumed as a proper measure forpitch, but we ask whether a mechanism based on strobe integration is a viable possibility.

People, especially when blind, use echolocation to detect obstacles, orient themselves and get an awareness of their environment. Echolocation describes how people use reflected sounds to obtain information about their ambient world. Echolocation with long canes while walking is possible but difficult. Different spectral composition of the emitted sounds from canes had no differential effects. Sound recordings in anechoic and conference rooms from non-walking, static situations, later presented in a laboratory showed a better performance in an ordinary room with reflections, than in an anechoic room. Longer sounding sounds resulted in a higher performance than short clicks. Among the difficulties for the blind are how to avoid masking of sounds. There may exist a time gap, acoustic gaze, for how blind people use clicks. The results of previous studies were reanalyzed by using auditory models. Thresholds based on local non-parametric fitting, were determined for distance, pitch, loudness and sharpness. The blind had overall a more sensitive threshold than sighted persons. A few blind are exceptionally high performing. An information-surplus principle' has been proposed. Various information sources are used, but repetition pitch seems more important than loudness for echolocation. Among other sources, timbre may also provide information.

Blind people use auditory information to locate sound sources and sound-reflecting objects (echolocation). Sound source localization benefits from the hearing system's ability to suppress distracting sound reflections, whereas echolocation would benefit from "unsuppressing" these reflections. To clarify how these potentially conflicting aspects of spatial hearing interact in blind versus sighted listeners, we measured discrimination thresholds for two binaural location cues: inter-aural level differences (ILDs) and inter-aural time differences (ITDs). The ILDs or ITDs were present in single clicks, in the leading component of click pairs, or in the lagging component of click pairs, exploiting processes related to both sound source localization and echolocation. We tested 23 blind (mean age = 54 y), 23 sighted-age matched (mean age = 54 y), and 42 sighted-young (mean age = 26 y) listeners. The results suggested greater ILD sensitivity for blind than for sighted listeners. The blind group's superiority was particularly evident for ILD-lag-click discrimination, suggesting not only enhanced ILD sensitivity in general but also increased ability to unsuppress lagging clicks. This may be related to the blind person's experience of localizing reflected sounds, for which ILDs may be more efficient than ITDs. On the ITD-discrimination tasks, the blind listeners performed better than the sighted age-matched listeners, but not better than the sighted young listeners. ITD sensitivity declines with age, and the equal performance of the blind listeners compared to a group of substantially younger listeners is consistent with the notion that blind people's experience may offset age-related decline in ITD sensitivity.

This study explored the ability of blind and sighted listeners to detect reflections, "echoes", of burst trains or continuous noise. Echo detection was compared by presenting 5 ms bursts, rates from 1 to 64 bursts, with a continuous white noise, all during 500 ms. Sounds were recorded in an ordinary room through an artificial binaural head, the loudspeaker 1 m behind it. The reflecting object was an aluminum disk, diameter 0.5 m, placed at 1 m. The sounds were presented to 12 blind and 26 sighted participants in a laboratory using a 2-Alternative-Forced-Choice methodology. The task was to detect which of two sounds contained an echo. In Experiment 2, 1.5 m distance sounds were presented to the blind only. At 1 m, detection for the blind increased up to 64 bursts/500 ms, but for the sighted up to 32 bursts. At 1.5 m, the peak performance for the blind was at 32 bursts. At the 1 m, but not at the 1.5 m distance, the blind performed best with continuous white noise. The overlap in time of signal and echo at 1 m for 64 bursts was 60%, but at 1.5 m 82%. Avoiding an overlap between emitted bursts and returning echoes seems important for echolocation, indicating that an acoustic gaze, analogous to in echolocating animals, may also exist in humans.

The Google search engine was studied as a Web prototype to be modified and improved for blind users. A Specialized Search Engine for the Blind (SSEB) was developed with an accessible interface and improved functions (searching assistance functions, user-centered functions, and specialized design for the blind). An experiment was conducted with twelve participants, both blind and sighted, to verify the effects of SSEB. The performance was better with the SSEB than with the Google search engine, and the participants also showed higher satisfactions with the SSEB. Interface considerations for designing an accessible Web site for blind users are important. The users of SSEB could in the future be expanded to include most, if not all, visually impaired people, since the World Wide Web and all Internet resources should ideally be accessible to everyone.