this article. 0738-4602/92/$4.00 1992 AAAI 58 AI MAGAZINE for the 1990s (Silberschatz, Stonebraker, and Ullman 1990)

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...

The Information Visualization and Exploration Environment (IVEE) is a system for automatic creation of dynamic queries applications. IVEE imports database relations and automatically creates environments holding visualizations and query devices. IVEE offers multiple visualizations such as maps and starfields, and multiple query devices, such as sliders, alphasliders, and toggles. Arbitrary graphical objects can be attached to database objects in visualizations. Multiple visualizations may be active simultaneously. Users can interactively lay out and change between types of query devices. Users may retrieve details-on-demand by clicking on visualization objects. An HTML file may be provided along with the database, specifying how details-ondemand information should be presented, allowing for presentation of multimedia information in database objects. Finally, multiple IVEE clients running on separate workstations on a network can communicate by letting one users actions affect the visua...

The automated discovery of knowledge in databases is becoming increasingly important as the world's wealth of data continues to grow exponentially. Knowledge-discovery systems face challenging problems from real-world databases which tend to be dynamic, incomplete, redundant, noisy, sparse, and very large. This paper addresses these problems and describes some techniques for handling them. A model of an idealized knowledge-discovery system is presented as a reference for studying and designing new systems. This model is used in the comparison of three systems: CoverStory, EXPLORA, and the Knowledge Discovery Workbench. The deficiencies of existing systems relative to the model reveal several open problems for future research.

Environmental data have inherent uncertainty which is often ignored in visualization. Meteorological stations and doppler radars, including their time series averages, have a wealth of uncertainty information that traditional vector visualization methods such as meteorological wind barbs and arrow glyphs simply ignore. We have developed a new vector glyph to visualize uncertainty in winds and ocean currents. Our approach is to include uncertainty in direction and magnitude, as well as the mean direction and length, in vector glyph plots. Our glyph shows the variation in uncertainty, and provides fair comparisons of data from instruments, models, and time averages of varying certainty. We also define visualizations that incorporate uncertainty in an unambiguous manner as verity visualization. We use both quantitative and qualitative methods to compare our glyphs to traditional ones. Subjective comparison tests with experts are provided, as well as objective tests, where the information density of our new glyphs and traditional glyphs are compared. The design of the glyph and numerous examples using environmental data are given. We show enhanced visualizations, data together with their uncertainty information, that may improve understanding of environmental vector field data quality.

We present a survey of multidimensional multivariate (mdmv) visualization techniques developed during the last three decades. This subfield of scientific visualization deals with the analysis of data with multiple parameters or factors, and the key relationships among them. The course of development is roughly organized into four stages, within which major milestones are discussed. Recently developed techniques are explored with examples. 1 Introduction Multidimensional multivariate visualization is an important subfield of scientific visualization. It was studied separately by statisticians and psychologists long before computer science was deemed a discipline. The appearance of low-priced personal computers and workstations during the 1980's breathed new life into graphical analysis of mdmv data. This research topic was among one of the short-term goals included in the 1987 National Science Foundation (NSF) sponsored workshop on Visualization in Scientific Computing [MDB87]. Th...

In analyzing abstract data sets, it is useful to represent them in several alternative formats, each format bringing out different aspects of the data. While most work in data mapping has focused on visual representations, we have found that sonic representations can also be effective aids in interpreting complex data, especially when sonification is used in conjunction with visualization. We have developed prototypes for several high-level sonification tools that can be applied to a wide variety of data. While we used programmable multi-processor digital signal processing hardware to develop and experiment with these prototypes, each of these tools could be implemented as special-purpose hardware or software for use by scientists in specific applications. Our prototype tools include: Mapper (maps data to various sonic parameters), Comparator (feeds a different mapping into each speaker channel), Sonic Histogram (maps the magnitude of each category onto the amplitude of its associated...

This paper presents a general model for sonification of large spatial data sets (e.g. seismic data, medical data) based on ideas from ecological acoustics. The model incorporates not only what we hear (the sounds), but also how we listen (the interaction). Metaphorically speaking the interpreter is walking along paths in areas of the data set, listening to locally and globally defined sound objects. The time aspects of sonification are given special attention, introducing the notion of temporalization. Some features of a preliminary Windows NT implementation are summarized. Keywords Sonification, ecological acoustics, everyday listening, interaction, model

vii Acknowledgements viii 1. Introduction 1 2. Sound 4 2.1 Definition : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 4 2.2 Properties of Discrete Sounds : : : : : : : : : : : : : : : : : : : : : : : : : : 4 2.2.1 Frequency : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 4 2.2.2 Amplitude : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 5 2.2.3 Location : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 5 2.2.4 Timbre : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 6 2.2.5 Envelope : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 6 2.2.6 Environmental Effects : : : : : : : : : : : : : : : : : : : : : : : : : : 7 2.3 Properties of Sound Sequences : : : : : : : : : : : : : : : : : : : : : : : : : 7 2.4 A Proposed Sound Model : : : : : : : : : : : : : : : : : : : : : : : : : : : : 7 2.5 Sound Hardware : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 9 2.6 So...

Mathematics is communicated in visual forms, such as algebra and diagrams. This means that blind people are greatly disadvantaged with respect to education and employment in mathematics, science and technology. A number of ideas are presented regarding the representation of mathematics in non-visual formats. In particular, the Mathtalk software for the presentation of algebra in synthetic speech, is described, as is Soundgraph a program which presents the graphs of mathematical functions in speech and non-speech sounds.