Subject: New Release of DSAM library, AMS and other software. From: "Lowel P. O'Mard" <lowel(at)ESSEX.AC.UK> Date: Thu, 5 Jun 2003 16:20:53 +0100New Release of DSAM library, AMS and other software. Hello, Summary ----------- We would like to announce the release of the latest version of the DSAM library, and related applications such as AMS and the new RunDSAMSim executable function for use in Matlab/Octave . The manual has been updated and redrafted creating a document which is easier to read and containing more useful information. The new release can be found from the 'Downloads' page at the following URL http://www.essex.ac.uk/psychology/hearinglab/dsam Overview ------------ The DSAM library has been subjected to extensive changes and improvements. Using the stability of the previous DSAM software as a starting point, many subtle bugs and other problems have been weeded out. Despite the changes, a great deal of effort has been made to ensure backwards compatibility with previous simulation scripts '*.sim' and/or simulation parameter files '*.spf'. The new AMS application has been tested for almost a year now by a faithful band of BETA testers. Improved Documentation ------------------------------- The manual has been redrafted. A new layout has been introduced to increase clarity and readability. It now contains additional information for many of the process modules, providing mathematical equations in the process descriptions. References have also been included for all published models. The documentation (DSAMHelp) can be installed along with AMS and other DSAM applications and will appear as online documentation. A PDF file will also soon be available. A series of tutorials is now available with the AMS application. These tutorials are available from the online help and provide worked examples which help to describe AMS and how it can be used. Simulation Scripts ---------------------- Among the many new features is the enhancement of simulation scripts. In AMS and other DSAM applications the simulation process flow is defined using simulations scripts. Simulation scripts are now much less restrictive as all process modules have default values. This means that a simple simulation script can be written thus: begin { Stim_PureTone # Stimulus generation. Trans_Ramp # Ramp stimulus. Filt_BandPass # Outer/Middle Ear filter model. BM_GammaT # Basilar membrane filter model. IHC_Meddis86 # Hair cell model. Display_Signal # Display output DataFile_Out # Save output to file. } The above simulation script will run using the default value for each of the processes. Parameter files can be used to set the process parameters to other value when required (or by using one of the other means of setting parameters in DSAM applications – see the documentation). It is also possible to depart from the simple pipe-line simulation shown above and produce more complex connections between processes using labels. Free-format parameter files --------------------------------- The process parameter file format has also changed. The files now consist of free-format text files, in which each line consists of a parameter name followed by its setting. Only the parameters that are being changed from their default values need to be put into the file. Old process parameter files will still work, though their use is deprecated. Display Improvements ---------------------------- Displays produced by AMS and other DSAM applications with GUI support have been improved. A faster drawing algorithm has been used, that uses memory more efficiently. The axis scaling has also been improved, offering nicer automatic scaling and a simple customisation method. Threaded Operation for Applications with GUI Support ------------------------------------------------------------------- Threaded operation has been implemented for AMS and other DSAM applications running using the graphical user inferface (GUI) support. This means that it is now possible to stop simulations while they are still running, without killing the whole process. In addition all displays will now open as soon as their data has been generated. This also means that you can be changing simulation parameters while the simulation is running. New Modules ----------------- Many new process modules have been added to the DSAM library. There are too many to adequately list here. Among the additions are two new complete nonlinear AN models. These include the 'Essex' nonlinear auditory nerve (AN) model , including the DRNL nonlinear basilar membrane (BM) filter model (Meddis R. Et al. 2001) and the new Meddis hair cell model ( Sumner C. Et al. 2002). There is also the 'Boston' nonlinear AN model (Zhang X. Et al. 2001) which as an improvement of the Carney non-linear model. Several of the existing process modules have been enhanced, though as previously mentioned backwards compatibility has been maintained. Matlab 6.5 support ----------------------- There is a new application, 'RunDSAMSim' which is included in the new AMS installation. This is a DSAM application dynamically linked with Matlab 6.5, and provides Matlab with complete control of simulations and results. Once the 'RunDSAMSim.dll' file is put into the matlab path, it can then be used in the same way as any Matlab command. Data can be passed to and from simulations using the function, and simulation parameters can be set. The RunDSAMSim application can also be compiled and dynamically linked with Octave (the freeware matlab clone). A separte installation package has yet to be set up for the RunDSAMSim application. It is currently supplied with the Windows AMS installation (as previously stated). Adding User Modules --------------------------- It is now easier for programmers to add their own modules. Users may now create their own modules to be used from within DSAM applications along with the existing library process modules. Modules are generated using the 'modgen' software tool using a simple definition file based on the process parameters. Current developments --------------------------- It will soon be possible to design simulations graphically. A simulation design interface (SDI) is being produced, and the development is in an advanced stage. The new interface will be available within a few months of the date of this announcement, if not sooner. New models are continually being developed and we are always happy to consider popular models for inclusion in the DSAM library. Important Future developments -------------------------------------- The next major development area is the introduction of threaded processing within DSAM. The introduction of threading within DSAM will enable it to better utilise today's processors (Pentium, Athlon, etc.) Threading will also allow DSAM to take full advantage of multi-processor systems and the new processors designed with increased threading in mind (incorporating 'Hyper-threading systems'). References ------------- Meddis R., O'Mard L. P. & Lopez-Poveda E. A. (2001) 'A computational algorithm for computing nonlinear auditory frequency selectivity' J. Acoust. Soc. Am., 109: 2852-2861. Sumner C., Lopez-Poveda E. A., O'Mard L. P. & Meddis R. (2002) 'A revised model of the inner-hair cell and auditory-nerve complex' J. Acoust. Soc. Am., [111], 2178-2188. Zhang X., Heinz M. G., Bruce, I C. & Carney L. H. (2001) 'A phenomenological model for the responses of auditory-nerve fibers: I. Nonlinear tuning with compression and suppression', J. Acoust. Soc. Am. [109], 648-670. -- _______________________________________________________________ Dr. Lowel P. M. O'Mard PhD. CNBH Essex, Dept. of Psychology, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK. http://www.essex.ac.uk/psychology/hearinglab/dsam