A Survey on the Affordances of “Hearables” <s> Introduction <s> Auditory Scene Analysis addresses the problem of hearing complex auditory environments, using a series of creative analogies to describe the process required of the human auditory system as it analyzes mixtures of sounds to recover descriptions of individual sounds. In a unified and comprehensive way, Bregman establishes a theoretical framework that integrates his findings with an unusually wide range of previous research in psychoacoustics, speech perception, music theory and composition, and computer modeling. <s> BIB001 </s> A Survey on the Affordances of “Hearables” <s> Introduction <s> Future health systems require the means to assess and track the neural and physiological function of a user over long periods of time, and in the community. Human body responses are manifested through multiple, interacting modalities – the mechanical, electrical and chemical; yet, current physiological monitors (e.g. actigraphy, heart rate) largely lack in cross-modal ability, are inconvenient and/or stigmatizing. We address these challenges through an inconspicuous earpiece, which benefits from the relatively stable position of the ear canal with respect to vital organs. Equipped with miniature multimodal sensors, it robustly measures the brain, cardiac and respiratory functions. Comprehensive experiments validate each modality within the proposed earpiece, while its potential in wearable health monitoring is illustrated through case studies spanning these three functions. We further demonstrate how combining data from multiple sensors within such an integrated wearable device improves both the accuracy of measurements and the ability to deal with artifacts in real-world scenarios. <s> BIB002
One of the goals of ubiquitous computing is that good technology will work seamlessly into our lives and workflows in such a way that we fail to even notice that it exists  . One major advancement towards this particular aim has been the advent and proliferation of wearable computing, in which computing devices are designed to be worn by the user for prolonged periods of time [2] . The large group of devices that fit within the realm of wearable computing are often referred to as "wearables", and include small and large fitness trackers (pedometers, accelerometers), smart watches, smart eyewear, and many other types of devices. In this paper, we examine a specific class of wearable devices that is mounted or attached to the ear(s); a class of wearables frequently referred to as "hearables"  . Nick Hunn has presented two working definitions of "hearables" the first, in 2014  , as any hearing device which included wireless connectivity, and later in 2016  , as "anything that fits in or on an ear that contains a wireless link, whether that's for audio, or remote control of audio augmentation". Thus, hearables represent a wide variety of devices, ranging from wireless audio headphones to smart hearing aids. While hearables are primarily designed for the presentation and recording of audio signals, there are many other possibilities for interaction, and these affordances are explored below. In line with both Gibson  and Gaver  , we use the term "affordances" to refer to attributes of an object that facilitate certain actions in a way that is independent (yet related) to the perception of the user. The affordances discussed below are general in nature, with each feature offering a range of uses and applications. The concept of affordances allows us to not only trace the history of ear-mounted devices and demonstrate how they have evolved, but also to provide insight into which affordances may provide the most utility for future applications. Hearables offer a number of unique computer-interface affordances, particularly due to the perceptual proclivities of human hearing. As opposed to the eyes, which may attend to only one view at a time, the ears are capable of decomposing complex auditory scenes BIB001 and selectively attending to certain sources, a phenomenon referred to as the cocktail party problem  . In this specific regard, hearables have great potential to "blend" into our everyday environments by focusing or ignoring incoming information, all while leaving the eyes free to attend to other tasks. The "eyes-free" feature of hearables is therefore one of their strongest affordances. Further, hearables are also referred to as "hands-free" devices, especially within the context of driving applications. This "eyes-and-hands-free" affordance of hearables ensures that they do not impede our abilities to visually or tactilely interact with the world, thus offering unique possibilities as computer interfaces. While hearables have a number of affordances for ubiquitous computing, many of these affordances are particularly relevant for affective computing, in which computers have the ability "to recognize, express, and "have" emotions"  . Hearables are particularly useful for recording affective data input, as the ear is a rich source for collecting many types of biological signals pertaining to our emotional states; ear-mounted sensors can potentially monitor cardiovascular, respiratory, perspiration, and brain states  BIB002 . This type of data has been utilized in a variety of different applications, including fitness tracking, health monitoring, improved computer interfaces, and various context-aware/"smart" systems. Traditionally, each type of application utilizes only a handful of the potential affordances offered by hearables. The aim of this paper is to bring awareness to the current and proposed affordances of hearables. It begins by tracing the evolution of headphones towards present-day hearables. Next, the affordances of hearables for ubiquitous computing systems are detailed, including those that have been exploited and several that remain theoretically possible. Thereafter, a comparison of hearables is made against other wearables. Finally, current and future trends are examined within existing and proposed hearables, and conclusions are drawn regarding the most immediate implications of these findings.