Automatic Generation of Audio Data in an Audio Framework IFI TR 93.42 November 1993 Helmut Schauer , Alireza Darvishi Department of Computer Science , University of Zurich , Switzerland darvishi@ifi.unizh.ch Matthias Rauterberg Work and Organizational Psychology Unit , Swiss Federal Institute of Technology -LRB- ETH -RRB- , Zurich , Switzerland rauterberg@rzvax.ethz.ch Massud Motavalli Swiss Federal Laboratories for Testing , Material , and Research , D?bendorf / ZH , Switzerland motavalli@empa.ch Scientific Information 1 . Summary of the Research Program The objective of this research program is the development of concepts , methods and a prototype for an audio framework . This audio framework shall describe sounds on a highly abstract semantic level . Every sound is to be described as the result of one or several interactions between one or several objects at a certain place and in a certain environment . Every interaction has attributes , that have an influence on the generated sound . Simultaneously , the participating objects , which take part in the sound generation process , can consist of different physical conditions -LRB- states of aggregation -RRB- , materials as well as their configurations in themselves also have attributes , which can have an influence on the generated sound . The hearing of sounds in everyday life is based on the perception of events and not on the perception of sounds as such . For this reason , everyday sounds are often described by the events they are based on . In the first place , a framework concept for the description of sounds is presented , in which sounds can be represented as auditive signal patterns along several descriptive dimensions of various objects interacting together in a certain environment . Based on the differentiation of purely physical and purely semantic descriptive dimensions , the automatic sound generation is discussed on the physical , syntactical and semantic levels . To be seen as physical descriptive dimensions are the sound pitch , frequency , volume and duration ; as semantic dimensions , the differentiation of the interacting objects with respect to their physical condition -LRB- status of aggregation -RRB- solid , liquid and gaseous has resulted . Within the scope of this research project , we shall especially look for possibilities to describe the sound class `` solid objects '' , in particular the class of the primitive sounds `` knock '' -LRB- `` strike '' , `` hit '' -RRB- , because this class of sounds 1 . -RRB- occurs very frequently in everyday life , 2 . -RRB- the interacting objects can be easily and well described by their material characteristics and 3 . -RRB- the knowledge of solid-state physics can be utilised . On the theoretical level , first of all a better overview and a better understanding of the capabilities , restrictions and problems of the existing instruments -LRB- tools -RRB- for the automatic generation of audio data can be anticipated . Out of the new concepts to be developed , essential impetuses for the following fields can result . * CAD - architecture : new possibilities for the representation of sound insulating rooms , walls , materials etc. . In general , the acoustics of buildings can be simulated and interactively modified . * Materials research : new possibilities for the interactive representation of hidden and thus only inadequately visually representable materials characteristics . * Multimedia : new possibilities for the interactive representation of complex sound generating events and processes . * User interfaces for people with impaired vision : simulations with the utilisation of audio data will in future also have their application in the training of people with impaired senses , in particular of people with damaged vision . 2 . Research Plan 2.1 . The State of Research Many computers have a sound-generator which produces a simple beep-sound to indicate the errors . For a long time the only audio-information for user-interfaces contemporary modern workstations have signal-processors and analogue-digital converters and therefore sounds can be used in software . 2.1.1 . Definition of Basic Terms The terms which are used later in this chapter are defined as follows : Audio signal pattern : description of all perceptible audio signals . Speech : the description of all audio signals which have describable grammar structures . Music : complex audio signal pattern which has rhythmic describable structures . Tone : simple audio signal pattern with rhythmic describable structure . Everyday-sounds : audio signal patterns which have not been sufficiently researched to give a description and creation structure . We call the combined group of everyday-sounds and tones `` sounds '' . When we mean the assignment of a sound to an event we put the event-identifier in inverted commas -LRB- for example : event = impact , sound = `` impact '' -RRB- . 2.1.2 . Comparison of Auditory and Visual Signal Pattern . Usability knowledge and experience in the domain area low high textual representation visual representation concrete representation low high Figure 1 When to use different representation media -LSB- Marmolin-92 :47 -RSB- . The textual representation of information is of most use when the user is familiar with the domain area and can demonstrate much experience and knowledge in that domain area . In comparison , more concrete -LRB- visual and auditory -RRB- representations of information which the user can query are of most use when the domain area is new and unknown . By comparing audio signal patterns with visual signal patterns the different advantages of each can be shown -LRB- see Table 1 -RRB- . Table 1 Comparison of auditory and visual signal patterns in time-space continuum -LSB- Gaver-89 :71 -RSB- . Time Dimension Space Dimension auditory Auditory signal patterns exists in time . ? They are well suited for changing events , ? accessible only for a limited time span . Auditory signal patters exists over space . ? They can be `` processed '' and do not require visual contact , ? only a limited number can be processed at the same time . visual Visual signal patterns exist over time . ? They are well suited for static objects , ? can be sampled over time . Visual signal patterns exist in space . ? They require active eye contact , ? messages can be spatially distributed . Sounds and music can be utilised to improve the user 's understanding of visual predecessors or can stand alone as independent sources of information . -LRB- For example : sounds as diagnostic support applied with the direction of a process simulation -LSB- Gaver-91 -RSB- -RRB- . The parallel use of different media and the resulting parallel distribution of information , for example by simultaneously showing a predecessor through a concrete representation and its explanation through audio distribution , leads to a denser sharing of information . In this case , the user can dedicate his attention solely to the visual information , which has parallel audio support . This reduces the need to change textual or other visual delivery and prevents the overflow of visual information -LSB- Gaver-91 -RSB- . The redundancy of information represented visually and auditory , as long as the representation of the information is realistically formed , is sensed not as disturbing , but instead it demands and increases information reception . It is important that with simultaneous information representation , that the information is harmonised together and that the different media are well synchronised . -LSB- Gaver-89 -RSB- Gaver , W. -LRB- 1989 -RRB- The SonicFinder : an interface that uses auditory icons . Human Computer Interaction 4:67 -94 . -LSB- Gaver-90 -RSB- Gaver , W. & Smith R. -LRB- 1990 -RRB- Auditory icons in large-scale collaborative environments . in D. Diaper , D. Gilmore , G. Cockton & B. Shackel -LRB- eds . -RRB- Human-Computer Interaction - INTERACT ' 90 . -LRB- pp. 735-740 -RRB- , Amsterdam : North-Holland . -LSB- Gaver-91 -RSB- Gaver , W. , Smith , R. & O'Shea , T. -LRB- 1991 -RRB- Effective sounds in complex systems : the ARKola simulation . in S. Robertson , G. Olson & J. Olson -LRB- eds . -RRB- , Reaching through technology CHI ' 91 . -LRB- pp. 85-90 -RRB- , Reading MA : Addison-Wesley . -LSB- Marmolin-92 -RSB- Marmolin , H. -LRB- 1992 -RRB- Multimedia from the perspective of psychology . in L. Kjelldahl -LRB- ed . -RRB- Multimedia : systems , interaction , and applications . Berlin , Heidelberg : Springer . 2.1.3 . Everyday Sound Perception The perception of auditory signal patterns in everyday life can come in very different forms : a car driving by on the street , a dripping faucet , the confusion of voices from a crowd of people , opera music , a plane flying by , the buzz of a travel alarm clock , the beeping of a wristwatch , etc. . All of these auditory signal patterns are divided into 4 categories : speech , music , sound and noise ; sometimes noises and sounds are heard and grouped together . All of these categories are described sufficiently in the physical world through the mixing and superposition of different pitches , frequencies , volumes and sound duration . One of the essential differences between these categories , however , lies in their semantics : Speech serves primarily to convey information , while music and noise can have a pleasant or an unpleasant influence on the emotions . For musicians and other people who are intimate with this area , music and noise have a comparable semantic and informative character as speech does for the normal citizen . Aside from music and noise , the listener is interested next in the possibility of undisturbed , context-free perception . In contrast to music and noise , everyday sounds have a self-standing characteristic ; they are extremely context sensitive and event related -LSB- Gaver-86 -RSB- . Through the physical interaction of different everyday objects in 3-D space the sounds of everyday life are created and through propagation they become audible through the air . In comparison with music and noises , the semantically relevant dimension of sound lies not with the characteristic quality of the auditory signal pattern itself , but rather with the quality of the sound producing event as it respects the concerned object -LSB- Mountford-90 -RSB- . This difference leads us to the conclusion that sounds are interpreted differently than music based upon their quality . When listening to music we are primarily interested in the effect of music on us ; while when hearing everyday sounds we are interested in the quality of the sound producing object and the accompanying circumstances -LRB- i.e. . surrounding conditions , events , etc. -RRB- . Of course , music can be heard from the perspective of every day use ; in this case the listener pays attention to the nature and tune of the instrument in use , to the tempo , to the acoustic , to the place of performance , etc. . This method of listening to music is dependent upon the listener 's knowledge of this domain field ; only someone who is experienced with music will be able to extract all of the various information from a piece of music . The average adult is , for the interpretation of everyday sounds , an expert with a large degree of knowledge from experience . This knowledge allows one to evaluate everyday sounds according to the following criteria for relevant information : 1 . Information about the physical occurrence : we hear , if the fallen glass clinks or breaks . 2 . Information about unseen structures : when knocking on the wall , we can hear if it is hollow . 3 . Information about dynamic changes : when filling a wine glass , we can hear when it is full and runs over . 4 . Information about abnormal conditions : we hear , when the car engine ceases to function properly and runs irregularly . 5 . Information about occurrences outside of the visual field : the sound of footsteps behind us `` tells '' us if someone is approaching . Listening to everyday sounds is based upon the perception of events and not upon the perception of sounds in and of themselves . This fact becomes clear in the following example : Illustrative example : A pen dropped upon a piece of paper from a height of about 15 cm created a different sound than when it is dropped upon the hard surface of a desk . An altogether different sound is created when a rubber eraser is dropped upon the paper or , respectively , on the desk . The sound created in each case of the previous example is neither a characteristic of any of the participating objects -LRB- pen , rubber eraser , sheet of paper , desk surface -RRB- nor a characteristic of the occurrence `` dropped '' itself . The four different sounds in the examples are , in terms of an observation that holds true to the reality of the situation solely determined by their respective interaction and environmental conditions . Everyday sounds are therefore due to a lack of better descriptive possibilities , often described through the underlying occurrence -LRB- see Table 2 -RRB- . Table 2 The nine possible combinations for sound-creating object interactions -LRB- Surroundings : = air , propagation medium : = `` air '' -RRB- Object type Ol : solid Ol : liquid Ol : gas Os : solid `` bells sounding '' clapper - > bell `` stirring '' wish - > cream `` archery '' arrow - > air Os : liquid `` pouring '' coffee - > cup `` spray '' stream - > pond `` raining '' drop - > air Os : gas `` rustling '' wind - > leaves `` boiling water '' air bubbles - > water `` exploding '' balloon - > air -LSB- Legend : Object -LRB- small , moving fast -RRB- `` Os '' interacts '' - > '' with Object -LRB- large , still , slow -RRB- `` Ol '' -RSB- Every sound is also a result of one or more interactions between two or more objects in a definite place and in definite surroundings and can be defined as the following : Sound = f -LRB- Interaction -LRB- s -RRB- , objects , surroundings , place , time -RRB- surroundings object-A object-B propagation medium ear Figure 2 Representation of all primary shared components with the production of everyday sounds Every interaction possesses attributes which have an influence on the produced sound . At the same time the shared objects can participate in the production of sound from different aggregate conditions , materials , and even their configuration . The configurations of these materials possess attributes that also can have an influence on the produced sound -LRB- Fig. 2 -RRB- . -LSB- Gaver-86 -RSB- Gaver , W. -LRB- 1986 -RRB- Auditory Icons : using sound in computer interfaces . Human Computer Interaction 2:167 -177 . -LSB- Mountford-90 -RSB- Mountford , S. & Gaver , W. -LRB- 1990 -RRB- Talking and listening to computers . in B. Laurel & S. Mountford -LRB- eds . -RRB- The Art of Human-Computer Interface Design . -LRB- pp. 319-334 -RRB- , Reading MA : Addison-Wesley . 2.1.4 . Existing Research Projects and Results With the manufacture and adaptation in the world of interactive computer systems -LRB- i.e. . multimedia applications -RRB- one must decide between the following three types of substitution : 1 . Propagation : here the quality of the propagation channel is important -LRB- i.e. bandwidth , etc. -RRB- ; 2 . Intake , saving , and reproduction : this is actually time synchronous with visual processing to add extra significance ; 3 . Automatic Production : in this area the realistic generation of context sensitive , auditory signal patterns has the most significance . We limit ourselves in this research proposal to the third area : the automatic production of sounds . The existing research estimates for audio estimates with interactive systems will be listed . The computer manufacturer , Apple , researches the substitution of audio media for improvement of graphical user interface and presents the so-called `` Auditory Icons '' such as `` Earcons '' -LSB- Gaver-86 -RSB- -LSB- Gaver-89 -RSB- -LSB- Gaver-90 -RSB- -LSB- Blattner-89 -RSB- . The Bell Communications Research Centre in collaboration with the Massachusetts Institute of Technology developed an `` Audio-Windowsystem '' as an analogue of the `` Visual Windowsystem '' which realised one , two , and three dimensional representations of auditory source -LSB- Ludwig-90 -RSB- -LSB- Wenzel-91 -RSB- . The Olivetti Research Center was developing a so-called `` Audio-Server '' an analogy to the `` Window-Server '' with a user interface based on the Client-Server Model -LSB- Binding-90 -RSB- . None of the three projects mentioned above , however , allow the description of sounds on a highly abstract semantic level . -LSB- Binding-90 -RSB- Binding , C. , Schmandt , C. , Lantz , K. & Arons , B. -LRB- 1990 -RRB- Workstation audio and window-based graphics : similarities and differences . in G. Cockton -LRB- ed . -RRB- Engineering for Human-Computer Interaction . -LRB- pp. 233-247 -RRB- , Amsterdam : North-Holland . -LSB- Blattner-89 -RSB- Blattner , M. et al. -LRB- 1989 -RRB- Earcons and Icons : their structure and common design principles . Human Computer Interaction , 4:11 -44 . -LSB- Gaver-86 -RSB- Gaver , W. -LRB- 1986 -RRB- Auditory Icons : Using Sound in Computer Interfaces . Human Computer Interaction , 2:167 -177 . -LSB- Gaver-89 -RSB- Gaver , W. -LRB- 1989 -RRB- The SonicFinder : An Interface That Uses Auditory Icons . Human Computer Interaction , 4:67 -94 . -LSB- Gaver-90 -RSB- Gaver , W. & Smith , R. -LRB- 1990 -RRB- Auditory icons in large-scale collaborative environments . in D. Diaper et al. -LRB- eds . -RRB- Human Computer Interaction INTERACT '90 -LRB- pp. 735-740 -RRB- . Amsterdam : Elsevier . -LSB- Gaver-91 -RSB- Gaver , W. -LRB- 1991 -RRB- The SonicFinder : An Interface That Uses Auditory Icons . Human Computer Interaction , 4:67 -94 . -LSB- Ludwig-90 -RSB- Ludwig L. , Pincever , N. & Cohen , M. -LRB- 1990 -RRB- Extending the notion of a window system to audio . Computer 23 -LRB- 8 -RRB- :66 -72 . -LSB- Smith-90 -RSB- Smith , S. , Bergeron R. & Grinstein , G. -LRB- 1990 -RRB- Stereophonic and surface sound for exploratory data analysis . in Proceedings of Computer-Human-Interaction CHI ' 90 . New York : ACM . -LSB- Wenzel-91 -RSB- Wenzel E. , Wightman F. & Kistler D. -LRB- 1991 -RRB- Localization with non-individualized virtual acoustic display cues . in S. Robertson , G. Olson & J. Olson -LRB- eds . -RRB- , Reaching through technology CHI ' 91 . -LRB- pp. 351-359 -RRB- , Reading MA : Addison-Wesley . 2.2 . The State of Own Research It is mainly the following factors in their respective forms and combinations which influence the load for humans in the man-computer interaction : the organization of the working-place and the working-place environment , the content of the tasks on the screen , the temporal share of the activity on the screen in proportion to the whole activity , the content of the computer-support and the user-friendliness of the interactive system . Our investigations have shown that the user-friendliness of a data-processing system crucially influences its acceptance by its users . Three different aspects should hereby be discriminated : -LRB- 1 -RRB- the functionality and the amount of information , -LRB- 2 -RRB- the availability -LRB- response-times and disturbances -RRB- and -LRB- 3 -RRB- the operational handling mediated by the user-interface -LSB- Rauterberg-91a -RSB- -LSB- Rauterberg-91b -RSB- -LSB- Rauterberg-91c -RSB- -LSB- Rauterberg-92a -RSB- -LSB- Rauterberg-92b -RSB- -LSB- Rauterberg-93 -RSB- . The results of an experiment for the investigation of the effects of audio-feedback showed , that the results of a database-query at the user-interface with an individually selectable acoustic feedback were as good as with a previously adjusted standard interface without any acoustic feedback . However , if the users who considered the acoustic feedback as useful are compared with those who considered it not necessary , significant performance-advantages result for the persons with a positive mind about the acoustic feedback . -LSB- Rauterberg-91d -RSB- -LSB- Rauterberg-91a -RSB- Rauterberg , M. -LRB- 1991 -RRB- . Benutzungsorientierte Benchmark-Tests : eine Methode zur Benutzerbeteiligung bei Standardsoftware-Entwicklungen . In : D. Ackermann & E. Ulich -LRB- eds . -RRB- , German Chapter of the ACM Berichte Nr . 32 `` Software-Ergonomie ' 91 '' , S. 96-107 , Stuttgart : Teubner . -LSB- Rauterberg-91b -RSB- Rauterberg , M. -LRB- 1991 -RRB- Benutzungsorientierte Benchmark-Tests : Anwendung auf die Gestaltung der Benutzungsoberfl?che von ADIMENS GT hin zu GT + . In : M. Rauterberg & E. Ulich -LRB- eds . -RRB- , Posterband zur Software-Ergonomie '91 -LRB- S. 151-162 -RRB- . Z?rich : ETH , Institut f?r Arbeitspsychologie . -LSB- Rauterberg-91c -RSB- Rauterberg , M. -LRB- 1991 -RRB- From passive to active joins : A task oriented desktop interface conception for a relational DataBase Management-System . Proceedings of the Conference `` Intelligent Text and Information Handling RIAO 91 '' Barcelona -LRB- Spain -RRB- - April 2-5 ,1991 . Vol . 2 -LRB- pp. 809-821 -RRB- . -LSB- Rauterberg-91d -RSB- Rauterberg M. , Baumgartner A. , Jenny A. & de Lange M. -LRB- 1991 -RRB- Erh?hung der Transparenz durch individualisierte Soundunterst?tzung bei Datenbankrecherchen . Technical Report IS-1-91 . Institut f?r Arbeitspsychologie . Z?rich : ETH . -LSB- Rauterberg-92a -RSB- Rauterberg , M. -LRB- 1992 -RRB- Designing and testing the usability of a relational data base system with end-user oriented benchmark tasks . In : P. Br?dner & W. Karwowski -LRB- eds . -RRB- , Ergonomics of Hybrid Automated System III -LRB- pp. 301 - 306 -RRB- . Amsterdam London Tokyo : Elsevier . -LSB- Rauterberg-93 -RSB- Rauterberg , M. -LRB- 1993 , in press -RRB- A product oriented approach to quantify usability attributes and the interactive quality of user interfaces . In : H. Luczak , A. Cakir & G. Cakir -LRB- eds . -RRB- , Work With Display Units -LRB- WWDU -RRB- . Amsterdam : Elsevier . 2.3 . The Research Plan in Detail 2.3.1 . Analysis of the Existing Models and Concepts First of all , the contemporary concepts and models in the field of structural mechanics have to be analysed and investigated for their appropriateness for this research-project -LRB- e.g. -LSB- Dual-88 -RSB- and -LSB- Koller-83 -RSB- -RRB- . In order to gain the knowledge from sound-specialists , the following `` knowledgeengineering '' methods are taken into consideration -LSB- Welbank-90 -RSB- : 1 . interviews with specialists in the field of film and radio ; 2 . observation of sound-engineers while they are producing sounds with solid objects -LRB- e.g. coconut-halves for the simulation of the clatter of hooves -RRB- 3 . multidimensional scaling of noises . -LSB- Dual-88 -RSB- Dual , J. -LRB- 1989 -RRB- Experimental Methods in Wave Propagation in Solids and dynamic Wiscometry . Dissertation Nr . 8659 , Z?rich : ETH . -LSB- Koller-83 -RSB- Koller , M. G. -LRB- 1983 -RRB- Elastischer Stoss von Kugeln auf dicke Platten . Dissertation Nr . 7299 , Z?rich : ETH . -LSB- Welbank-90 -RSB- Welbank , M. -LRB- 1990 -RRB- An overview of knowledge acquisition methods . Interacting with Computers . 2 -LRB- 1 -RRB- :83 -91 . 2.3.2 . Definition of the Requirement From the analysis of existing models and concepts as well as empirical investigations of the pre-phase a definition for the requirements for a new concept and a new model should be derived . 2.3.3 . Object-Oriented Design The example of the impact of a falling ball on the surface of a plate shows the physical process of producing sound through the interaction of the objects ball and plate -LRB- see Fig. 3 -RRB- . restoring forces -LRB- elasticity , tension -RRB- potential energy kinetic energy 1 . -RRB- Deformation 2 . -RRB- Return 3 . -RRB- Overshooting external force potential energy kinetic energy potential energy kinetic energy Figure 3 The relation ship between potential and kinetic energy when a solid plat is deformed by external forces -LSB- Gaver-93 -RSB- . The produced sound `` ball hits the plate '' can be described by the behaviour of the vibration of the surface , which has been produced by the deformation resulting from the fall of the ball . `` When an object is deformed by an external force , internal restoring forces cause a build up potential energy -LRB- 1 -RRB- . When the external force is removed , the object 's potential energy is transformed to kinetic energy , and it swings through its original position -LRB- 2 -RRB- . The object continues to vibrate until the initial input of energy is lost -LRB- 3 -RRB- '' -LSB- Gaver-93 -RSB- . The following presentation should help us to find a classification to describe the sounds on a very high abstract and semantic level . The following diagram -LRB- Fig. 4 -RRB- shows a global classification of everyday sounds regarding to the aggregation state of the interacting objects . interacting objects solid liquid gas - `` push '' - `` break '' - etc. . - `` drop '' - `` sprinkle '' - etc. . - `` explode '' - `` stream '' - etc. . level-I level-II level-III Figure 4 Sound classification of objects regarding to their aggregation state . The highest level in Figure 4 shows the class of everyday-sounds which are produced via interaction of two or more objects . The second highest level shows the three different material states which produce qualitatively diverse sounds via the interaction of two or more solid-objects produce sounds like `` push '' , `` break '' . Sounds like `` drop '' , `` sprinkle '' are produced via interaction of different liquid objects , and sounds like `` explode '' , `` stream '' are produced via aero-dynamic interactions in the air . All of these so-called `` primitive-sounds '' are characteristic f for their classes . The described sound-classification is very similar to the object oriented soft-ware development . In fact the object oriented concepts provide good and powerful tools in designing the above-mentioned sound-classification . Objectoriented soft-ware concepts are appropriate in many cases for soft-wareengineering paradigms . -LSB- Gaver-93 -RSB- Gaver , W. -LRB- 1993 , in press -RRB- What in the World do We Hear ? An Ecological Approach to Auditory Event Perception . Ecological Psychology 5 -LRB- 1 -RRB- . 2.3.4 . Audio-Framework The term `` framework '' comes from the object oriented world and is understood as follows : already programmed-frames which allow the programmers to supplement the application of specific parts in a program . An audio-framework should in the term of object oriented terminology provide the basic-sound classes and the possibilities to combine and manipulate them . At the moment there is no such audio-framework . As an example we are going to approach the sound-class `` impacts '' . Our approach : Our methodology can be demonstrated by dropping a ball onto a flat plate and later onto a non-flat plate . The four following steps are discussed : Step one : calculation of contact-force f -LRB- t -RRB- . It can be shown that the force f -LRB- t -RRB- can be derived from a differential equation -LSB- Koller-83 -RSB- . The calculated contact-force is a function of material-features -LRB- for example density , elasticity-module and mass -RRB- , geometry of contact-objects -LRB- for example the thickness of the ball , radius of the ball -RRB- and boundary conditions -LRB- for example the initial speed -RRB- . Step two : the calculation of deformation-function w -LRB- t -RRB- ; from so-called plate differential-equation and via some mathematical operations . Step three : Fourier-transformation of the function w -LRB- t -RRB- ; finally this function can be transformed via the Fourier method : Different frequencies can be produced as sounds -LSB- Ackermann-91 -RSB- . Using non-flat plates can cause complex mechanical-equations . For their solution they must be numerically integrated -LSB- Sayir-92 -RSB- . -LSB- Ackermann-91 -RSB- Ackermann , P. -LRB- 1991 -RRB- Computer und Musik , eine Einf?hrung in die digitale Klang - und Musikverarbeitung . Berlin : Springer . -LSB- Dong-62 -RSB- Dong , S. B. , Pister , K. S. & Taylor , R. L. -LRB- 1962 -RRB- On the theorie of Laminated on Isotropic shells and plates . Journal of Aerospace Science , 29:969 -975 . -LSB- Sayir-92 -RSB- Sayir , M. B. , H?usler , K. & Partel , M. -LRB- 1992 -RRB- Impact Behavior of corrugated sheets of fibre-reinforced cement . Composites , 23 -LRB- 6 -RRB- . 2.3.5 . Developing a Prototype Modern workstations like `` NEXT '' provide sound and music kits . They also provide so-called basic operations for manipulation of sound-patterns in the frequency-level . In addition they offer the opportunity to assign a digitizied sound to a certain dialogue-element , for example a button . All of these approaches assign an unchangeable sound to a object or operation . These sounds are very synthetic . It means contexfree and does not fulfil our expectation of the real world . Instead of that we understand a sound as a result of one or more interactions between two or more objects in a certain place and a certain environment . It means that a sound can convey more information about the sound-source , it 's place and environment . Therefore it should be calculated in real-time and is context-sensitive . 2.4 . The Importance of the Research Project On the theoretical level a better overview and understanding of the skills and restrictions of existing tools for automatic generation of audio-data are expected . The new concepts which are planned for development will give a basic impulse to the following fields : CAD : Architecture : New possibilities of examining the sound-isolation of rooms , walls , materials etc. . Generally , the acoustics of buildings could be changed and checked interactively . Material-research : New possibilities for hidden and unseen material-features . Multimedia : New possibilities for interactive creation of sound producing events and actions . Simulation : computer support learning A pedagogic target of computer support learning will clarify the processes . These processes could be physical or chemical processes . User interfaces for the visually impaired : Simulations also find their applications in the future for handicapped and especially visually impaired computer users , e. g. blind computer users could recognise the dialogue-objects and movable-pictures in a 3-D space via sounds in addition to the synthesisers .

O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

auditive feedback
human - computer interaction
knowledge engineering
non speech sound generation
object oriented programming
software engineering
software ergonomics
user interface management system