Profanity is nearly as old as language itself, and cursing has become particularly ubiquitous within the last century. At the same time, robots in personal and service applications are often overly polite, even though past work demonstrates the potential benefits of robot norm-breaking. Thus, we became curious about robots using curse words in error scenarios as a means for improving social perceptions by human users. We investigated this idea using three phases of exploratory work: an online video-based study (N = 76) with a student pool, an online video-based study (N = 98) in the general U.S. population, and an in-person proof-of-concept deployment (N =52) in a campus space, each of which included the following conditions: no-speech, non-expletive error response, and expletive error response. A surprising result in the outcomes for all three studies was that although verbal acknowledgment of an error was typically beneficial (as expected based on prior work), few significant differences appeared between the non-expletive and expletive error acknowledgment conditions (counter to our expectations). Within the cultural context of our work, the U.S., it seems that many users would likely not mind if robots curse, and may even find it relatable and humorous. This work signals a promising and mischievous design space that challenges typical robot character design.

Sound can benefit human-robot interaction, but little work has explored questions on the design of nonverbal sound for robots. The unique confluence of sound design and robotics expertise complicates these questions, as most roboticists do not have sound design expertise, necessitating collaborations with sound designers. We sought to understand how roboticists and sound designers approach the problem of robot sound design through two qualitative studies. The first study followed discussions by robotics researchers in focus groups, where these experts described motivations to add robot sound for various purposes. The second study guided music technology students through a generative activity for robot sound design; these sound designers in-training demonstrated high variability in design intent, processes, and inspiration. To unify the two perspectives, we structured recommendations through the design thinking framework, a popular design process. The insights provided in this work may aid roboticists in implementing helpful sounds in their robots, encourage sound designers to enter into collaborations on robot sound, and give key tips and warnings to both.

Nonverbal sound offers great potential to enhance robots’ interactions with humans, and a growing body of research has begun to explore nonverbal sound for tasks such as sound source localization, explicit communication, and improving sociability. However, nonverbal sound has a broad interpretation and design space that can draw from areas such as machine learning, music theory, and foley. We sought to identify and compare use cases and approaches for nonverbal sound in human-robot interaction through a systematic review. A search of sound and robotics-related publisher databases yielded 148 peer-reviewed articles presenting systems, studies, and taxonomies. Differences in taxonomy and overlap of terminology with adjacent research fields such as speech, gaze, and gesture posed difficulties for the search, which we attempted to address through a multi-stage search process. Based on the reviewed articles, we developed a pair of taxonomies using scientific communication principles and analyzed study designs and measures for the creation of nonverbal robot sound. We discuss recommendations for the field, including the use of the new taxonomies; methods for design, generation, and validation; and paths for future research. Roboticists may benefit from incorporating nonverbal sound as a key component in multimodal human-robot interaction.

Transformative robot sound can improve perceptions of robots, but its implementation will likely require more hardware and cost. Does the addition of transformative sound yield an increase in value to offset this cost? Using the van Westendorp Price Sensitivity Meter, a questionnaire from marketing research, n = 97 participants measured acceptable price points for a robot with (and without) transformative sound. Results showed similar perceptual improvements as past studies, as well as a significant increase in perceived value, when transformative sound was included. These increases in social and value perceptions of robots confirm the utility of adding transformative sound to robots. This work benefits the broader human-robot interaction research community by sharing more ways to understand and validate the incorporation of transformative robot sound and other robot features.

Lovable robots in movies regularly beep, chirp, and whirr, yet robots in the real world rarely deploy such sounds. Despite preliminary work supporting the perceptual and objective benefits of intentionally-produced robot sound, relatively little research is ongoing in this area. In this paper, we systematically evaluate transformative robot sound across multiple robot archetypes and behaviors. We conducted a series of five online video-based surveys, each with N≈ 100 participants, to better understand the effects of musician-designed transformative sounds on perceptions of personal, service, and industrial robots. Participants rated robot videos with transformative sound as significantly happier, warmer, and more competent in all five studies, as more energetic in four studies, and as less discomforting in one study. Overall, results confirmed that transformative sounds consistently improve subjective ratings but may convey affect contrary to the intent of affective robot behaviors. In future work, we will investigate the repeatability of these results through in-person studies and develop methods to automatically generate transformative robot sound. This work may benefit researchers and designers who aim to make robots more favorable to human users.

All robots create consequential sound—sound produced as a result of the robot’s mechanisms—yet little work has explored how sound impacts human-robot interaction. Recent work shows that the sound of different robot mechanisms affects perceived competence, trust, human-likeness, and discomfort. However, the physical sound characteristics responsible for these perceptions have not been clearly identified. In this paper, we aim to explore key characteristics of robot sound that might influence perceptions. A pilot study from our past work showed that quieter and higher-pitched robots may be perceived as more competent and less discomforting. To better understand how variance in these attributes affects perception, we performed audio manipulations on two sets of industrial robot arm videos within a series of four new studies presented in this paper. Results confirmed that quieter robots were perceived as less discomforting. In addition, higher-pitched robots were perceived as more energetic, happy, warm, and competent. Despite the robot’s industrial purpose and appearance, participants seemed to prefer more "cute" (or "kawaii") sound profiles, which could have implications for the design of more acceptable and fulfilling sound profiles for human-robot interactions with practical collaborative robots.

Robots have unique abilities to influence people, but when deploying robotic systems in assistive applications, roboticists must understand how users perceive these systems’ behaviors. As part of an ongoing project to use robots as motivational break-taking aids, we present Cozmo behaviors that could function as the action space of a future robot learning strategy. Before deploying these behaviors in the wild, we evaluated them using an online video-based study with N = 113 participants. Results show that participant perceptions of Cozmo behaviors tend to match the intended valence and energy level. Furthermore, behavior valence in particular has a strong bearing on other perceived characteristics such as interaction appeal, trustworthiness, and safety. Facial expression and loudness acted as important covariates, which may help generalize these results to other behaviors and robots. The products of this work can benefit those who are interested in robot emotional expression and assistive robot applications.

More than ever, people spend the workday seated in front of a computer, which contributes to health issues caused by excess sedentary behavior. While breaking up long periods of sitting can alleviate these issues, no scalable interventions have had long-term success in motivating activity breaks at work. We believe that socially assistive robotics (SAR), which combines the scalability of e-health interventions with the motivational social ability of a companion or coach, may offer a solution for changing sedentary habits. To begin this work, we designed a SAR system and conducted a within-subjects study with N = 19 participants to compare their experiences taking breaks using the SAR system versus an alarm-like device for one day each in participants' normal workplaces. Results indicate that both systems had similar effects on sedentary behavior, but the SAR system led to greater feelings of pleasure, enjoyment, and engagement. Interviews yielded design recommendations for future systems. We find that SAR systems hold promise for further investigations of aiding healthy habit formation in work settings.