A menu-driven computer application is presented that automates the evaluation of nonlinear filterbanks used to characterise the response of the basilar membrane (BM) to simple and complex sounds. It is important to show that a BM simulator reproduces the range of complex features observed in experiments and it is useful to have a convenient means of producing the evaluation functions typically used by experimentalists. Accordingly, the filter evaluation application (FEval) calculates the following functions: tuning curves, input/output functions, filter shapes, phase/intensity and phase/frequency functions, two-tone suppression ratios, two-tone responses, impulse responses and distortion products. The results are output to files in formats that are compatible with post-processing packages such as Excel and Matlab. Using DSAM 'simulation scripts' any model produced using process modules (models or functions) already available in DSAM can be tested. In the current case, FEval has been used to compared the outputs of three nonlinear filterbanks the original model of Carney (1993), the Dual Resonance Non-linear filter of Meddis et al. (submitted to JASA) and the Gammachirp filters of Irino and Patterson (1997). FEval is the newest addition to the family of applications based on the Development System for Auditory Modelling (DSAM). All DSAM applications employ a similar interface and inherit its features. Like other DSAM applications FEval allows a variety of interface options. There is a graphical user interface (GUI) that provides comprehensive access to model and evaluation test parameters. FEval can be started in 'server' mode that can then be controlled from the command line, manually, or by using Matlab or a similar scripting tool. FEval accepts command-line options giving access to all parameters, so it can be employed to produce quite complex analysis runs. FEval also has a command-line only version, for fast processing. FEval is available as an "out of the box" Windows installation (95/98/2000 and NT) for PC's, Linux RPM's, can be installed on UNIX machines using its auto-configuration system, and is easily ported to other systems.

References

Carney, L. H. (1993), "A model for the response of low-frequency auditory-nerve fibers in cat" JASA 93, 401-417.

Irino T. and Patterson R.D. (1997) "A time-domain level-dependent auditory filter", J. Acoust. Soc. Am. 101, 412-419.

DSAM: ( http://www.essex.ac.uk/psychology/hearinglab/dsam).

Meddis R., O'Mard L. P. and Lopez-Poveda A. E, "A computational algorithm for computing non-linear auditory frequency selectivity", in press. (what journal??? Xxx)

Electrical abstract

[MS Word file] (23.5 kB)