This paper gives HRTF magnitude data in numerical form for 43 frequencies between 0.2---12 kHz, the average of 12 studies representing 100 different subjects. However, no phase data is included in the tables; group delay simulation would need to be included in order to account for ITD. In 3-D sound applications intended for many users, we want might want to use HRTFs that represent the common features of a number of individuals. But another approach might be to use the features of a person who has desirable HRTFs, based on some criteria. (One can sense a future 3-D sound system where the pinnae of various famous musicians are simulated.) A set of HRTFs from a good localizer (discussed in Chapter 2) could be used if the criterion were localization performance. If the localization ability of the person is relatively accurate or more accurate than average, it might be reasonable to use these HRTF measurements for other individuals. The Convolvotron 3-D audio system (Wenzel, Wightman, and Foster, 1988) has used such sets particularly because elevation accuracy is affected negatively when listening through a bad localizers ears (see Wenzel, et al., 1988). It is best when any single nonindividualized HRTF set is psychoacoustically validated using a 113 statistical sample of the intended user population, as shown in Chapter 2. Otherwise, the use of one HRTF set over another is a purely subjective judgment based on criteria other than localization performance. The technique used by Wightman and Kistler (1989a) exemplifies a laboratory-based HRTF measurement procedure where accuracy and replicability of results were deemed crucial. A comparison of their techniques with those described in Blauert (1983), Shaw (1974), Mehrgardt and Mellert (1977), Middlebrooks, Makous, and Gree...

Note that the text that appeared in printed journal contains very minor typographic and grammatical corrections that do not appear in this version. SpeechSkimmer:

Although systems for animating algorithms are becoming more powerful and easier for programmers to use, not enough attention has been given to the techniques that an algorithm animator needs to create effective visualizations. This paper reviews the techniques for algorithm animation reported in the literature thus far and introduces new techniques that we have developed for using color and, to a lesser extent, sound. The paper also presents six algorithm animations that illustrate the new techniques. A videotape of these animations is available.

Most hypermedia systems emphasize the integration of graphics, images, video, and audio into a traditional hypertext framework. The hyperspeech system described in this paper, a speech-only hypermedia application, explores issues of navigation and system architecture in an audio environment without a visual display. The system under development uses speech recognition to maneuver in a database of digitally recorded speech segments; synthetic speech is used for control information and user feedback. In this research prototype, recorded audio interviews were segmented by topic, and hypertext-style links were added to connect logically related comments and ideas. The software architecture is data driven, with all knowledge embedded in the links and nodes, allowing the software that traverses through the network to be straightforward and concise. Several user interfaces were prototyped, emphasizing different styles of speech interaction and feedback between the user and machine. In additio...

Representations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84 Choosing Sounds for Mercator - A Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85 ix Designing Auditory Icons - A Different Perspective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Can Auditory Icons be Abstract? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Designing Sets of Auditory Cues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Chapter V Mercator Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 Information Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Modifications to Xt and Xlib . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Protocol Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Replacing the Pseudoserver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Control Flow. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 Interface Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

There are a variety of potential uses for interactive spatial sound in human-computer interfaces, but hardware costs have made most of these applications impractical. Recently, however, single-chip digital signal processors have made real-time spatial audio an affordable possibility for many workstations. This paper describes an efficient spatialization technique and the associated computational requirements. Issues specific to the use of spatial audio in user interfaces are addressed. The paper also describes the design of a network server for spatial audio that can support a number of users at modest cost. Introduction There are two basic ways of making two-channel audio recordings. The most common is stereo. A stereo recording captures differences in intensity and, possibly, differences in phase between points in a sound field. From these differences, the listener can gain a sense of the movement and position of a sound source. However, the perceived position of a sound source is u...

CONTENTS Executive Summary .................................................................................................................................... 154 Introduction .................................................................................................................................................156 Overview .....................................................................................................................................................156 Perception ...................................................................................................................................................157 Vision Audition Haptics Motion Sickness in Virtual Environments Virtual Environments in Perception Research Evaluation of Virtual Environments Human-Computer Software Interface .........................................................................................................163 Software .......................................................

We describe key affordances required by tools for developing haptic behaviors. Haptic icon design involves the envisioning, expression and iterative modification of haptic behavior representations. These behaviors are then rendered on a haptic device. For example, a sinusoidal force vs. position representation rendered on a haptic knob would produce the feeling of detents. Our contribution is twofold. We introduce a custom haptic icon prototyper that includes novel interaction features, and we then use the lessons learnt from its development plus our experiences with a variety of haptic devices to present and argue high-level design choices for such prototyping tools in general.

more. This is a test of the abstract. Write stuff here, and more, and more and more and Here is some more text The visceral emotional reactions that users have to technologies is increasingly understood to be important in terms of safety, performance, and pleasure in its own right. This thesis systematically explores users’s emotional (affect) reactions to everyday physical manual controls, in order to inform a design process that considers appropriate affective response as well as performance relationships. Design of both mechanical and emerging mechatronic physical controls are addressed. This novel design process includes parameterizing second order (inertial) dynamics using a system identification technique, and rendering models on a custom force-feedback knob. Next, this thesis explores biometric and self-reported measures of the affective responses elicited by these dynamics, and an iterative prototyping tool for rapid refinement of the “feel ” of physical controls. This research impacts use of the pas-sive physical interfaces such as mechanical knobs and sliders that are already ubiquitous

Screen-readers ---computer software that enables a visually impaired user to read the contents of a visual display--- have been available for more than a decade. Screen-readers are separate from the user application. Consequently, they have little or no contextual information about the contents of the display. The author has used traditional screen-reading applications for the last five years. The design of the speech-enabling approach described here has been implemented in Emacspeak to overcome many of the shortcomings he has encountered with traditional screen-readers. The approach used by Emacspeak is very different from that of traditional screen-readers. Screen-readers allow the user to listen to the contents appearing in different parts of the display; but the user is entirely responsible for building a mental model of the visual display in order to interpret what an application is trying to convey. Emacspeak, on the other hand, does not speak the screen. Instead, applications pr...