Sensory substitution systems provide their users with environmental information through a human sensory channel (eye, ear, or skin) different from that normally used or with the information processed in some useful way. The authors review the methods used to present visual, auditory, and modified tactile information to the skin and discuss present and potential future applications of sensory substitution, including tactile vision substitution (TVS), tactile auditory substitution, and remote tactile sensing or feedback (teletouch). The relevant sensory physiology of the skin, including the mechanisms of normal touch and the mechanisms and sensations associated with electrical stimulation of the skin using surface electrodes (electrotactile, or electrocutaneous, stimulation), is reviewed. The information-processing ability of the tactile sense and its relevance to sensory substitution is briefly summarized. The limitations of current tactile display technologies are discussed, and areas requiring further research for sensory substitution systems to become more practical are suggested. >

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Electrotactile and vibrotactile displays for sensory substitution systems

We present a new technology for enhancing touch interfaces with tactile feedback. The proposed technology is based on the electrovibration principle, does not use any moving parts and provides a wide range of tactile feedback sensations to fingers moving across a touch surface. When combined with an interactive display and touch input, it enables the design of a wide variety of interfaces that allow the user to feel virtual elements through touch. We present the principles of operation and an implementation of the technology. We also report the results of three controlled psychophysical experiments and a subjective user evaluation that describe and characterize users' perception of this technology. We conclude with an exploration of the design space of tactile touch screens using two comparable setups, one based on electrovibration and another on mechanical vibrotactile actuation.

TeslaTouch: electrovibration for touch surfaces

This report incorporates the views expressed at the workshop of leading experts from government, academia, and private sector, and detailed in contributions submitted thereafter by members of the U.S. science and engineering community. Acknowledgements The contribution of all participants in this study in developing a coherent vision for Converging Technologies for Improving Human Performance is acknowledged. The initial group that began planning this study in Spring 2001 is composed W. About the cover: The arrow suggests the combined role of nanotechnology, biotechnology, information technology in accelerating advancement of mental, physical, and overall human performance. This report was prepared under the guidance of NSET. Any opinions, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the United States Government.

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Converging technologies for improving human performance

Overview.- General Statements and Visionary Projects.- A. Motivation and Outlook.- B. Expanding Human Cognition and Communication.- C. Improving Human Health and Physical Capabilities.- D. enhancing Group and Societal Outcomes.- E. National Security.- F. Unifying Science and Education.- Appendices.- A. List of Participants and Contributors.- B. Index of Authors.- C. Index of Topics.

Converging Technologies for Improving Human Performance: Nanotechnology, Biotechnology, Information Technology and Cognitive Science

Tactile displays are now becoming available in a form that can be easily used in a user interface. This paper describes a new form of tactile output. Tactons, or tactile icons, are structured, abstract messages that can be used to communicate messages non-visually. A range of different parameters can be used for Tacton construction including: frequency, amplitude and duration of a tactile pulse, plus other parameters such as rhythm and location. Tactons have the potential to improve interaction in a range of different areas, particularly where the visual display is overloaded, limited in size or not available, such as interfaces for blind people or in mobile and wearable devices. This paper describes Tactons, the parameters used to construct them and some possible ways to design them. Examples of where Tactons might prove useful in user interfaces are given.

Tactons: Structured Tactile Messages for Non-Visual Information Display

The contribution of reduced speaking rate to the intelligibility of “clear” speech (Picheny, Durlach, & Braida, 1985) was evaluated by adjusting the durations of speech segments (a) via nonuniform ...

Speaking Clearly for the Hard of Hearing IV: Further Studies of the Role of Speaking Rate

In this work, the tactual information transmission capabilities of a tactual display designed to provide stimulation along a continuum from kinesthetic movements to cutaneous vibrations are assessed. The display is capable of delivering arbitrary waveforms to three digits (thumb, index, and middle finger) within an amplitude range from absolute detection threshold to about 50 dB sensation level and a frequency range from dc to above 300 Hz. Stimulus sets were designed at each of three signal durations (125, 250, and 500 msec) by combining salient attributes, such as frequency (further divided into low, middle, and high regions), amplitude, direction of motion, and finger location. Estimated static information transfer (IT) was 6.5 bits at 500 mseC., 6.4 bits at 250 mseC., and 5.6 bits at 125 msec. Estimates of IT rate were derived from identification experiments in which the subject’s task was to identify the middle stimulus in a sequence of three stimuli randomly selected from a given stimulus set. On the basis of the extrapolations from these IT measurements to continuous streams, the IT rate was estimated to be about 12 bits/seC., which is roughly the same as that achieved by Tadoma users in tactual speech communication.

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Information transmission with a multifinger tactual display.

In Tadoma, speech is received by placing a hand on the talker's face and monitoring actions associated with speech production. Our initial research has documented the speech perception, speech production, and linguistic abilities of deaf-blind individuals highly trained in Tadoma. This research has demonstrated that good speech reception can be achieved through the tactile sense: Performance is roughly equivalent to that of normals listening in noise or babble with a signal-to-noise ratio in the range 0-6 dB. It appears that the principal cues employed are lip movement, jaw movement, oral airflow, and laryngeal vibration, and that the errors which occur are caused primarily by inadequate information on tongue position. Our current research includes (1) learning of Tadoma by normal subjects with simulated deafness and blindness, (2) augmenting Tadoma with a supplemental tactile display of tongue position, and (3) developing a synthetic Tadoma system in which signals recorded from a talker's face are used to drive an artificial face. This research is expected to increase our understanding of Tadoma and its relation to other tactile communication methods, show that performance obtained through Tadoma does not represent the ultimate limits of the tactile sense, and provide a research tool for studying transformations of Tadoma.

Research on the Tadoma method of speech communication

Hearing aids--a review of past research on linear amplification, amplitude compression, and frequency lowering.

This paper is concerned with investigating the factors that contribute to optimizing information transfer (IT) rate in humans With an increasing interest in designing complex haptic signals for a wide variety of applications, there is a need for a better understanding of how information can be displayed in an optimal way Based on the results of several early studies from the 1950s, a general “rule of thumb” has arisen in the literature which suggests that IT rate is dependent primarily on the stimulus delivery rate and is optimized for presentation rates of 2-3 items/s Thus, the key to maximizing IT rate is to maximize the information in the stimulus set Recent data obtained with multidimensional tactual signals, however, appear to contradict these conclusions In particular, these current results suggest that optimal delivery rate varies with stimulus information to yield a constant peak IT rate that depends on the degree of familiarity and training with a particular stimulus set We discuss factors that may be responsible for the discrepancies in results across studies including procedural differences, training issues, and stimulus-response compatibility These factors should be taken into account when designing haptic signals to yield optimal IT rates for communication devices

Charlotte M. Reed

Papers

Speaking Clearly for the Hard of Hearing IV: Further Studies of the Role of Speaking Rate

Information transmission with a multifinger tactual display.

Research on the Tadoma method of speech communication

Hearing aids--a review of past research on linear amplification, amplitude compression, and frequency lowering.

Optimum Information Transfer Rates for Communication through Haptic and Other Sensory Modalities