Mercurial > hg > aim92
diff man/man1/genepn.1 @ 0:5242703e91d3 tip
Initial checkin for AIM92 aimR8.2 (last updated May 1997).
author | tomwalters |
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date | Fri, 20 May 2011 15:19:45 +0100 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/man/man1/genepn.1 Fri May 20 15:19:45 2011 +0100 @@ -0,0 +1,148 @@ +.TH GENEPN 1 "11 May 1995" +.LP +.SH NAME +.LP +genepn \- generate excitation pattern +.LP +.SH SYNOPSIS +.LP +genepn [ option=value | -option ] [ filename ] +.LP +.SH DESCRIPTION +.LP +Genepn converts the input wave into a simulated neural activity +pattern (NAP) and summarises the NAP as a sequence of excitation +patterns (EPNs). The operation takes place in three stages: spectral +analysis, neural encoding, and temporal integration. In the spectral +analysis stage, the input wave is converted into an array of filtered +waves, one for each channel of a gammatone auditory filterbank. The +surface of the array of filtered waves is AIM's representation of +basilar membrane motion (BMM) as a function of time (see genbmm). In +the neural encoding stage, compression, adaptation and, optionally, +suppression, are used to convert each wave from the filterbank into a +simulation of the aggregate neural response to that wave. The array of +responses is AIM's simulation of the neural activity pattern (NAP) in +the auditory nerve at about the level of the cochlear nucleus (see +gennap). Finally, the NAP is converted into a sequence of excitation +patterns (EPNs) by calculating the envelope of the NAP and extracting +spectral slices from the envelope every 'frstep_epn' ms. The envelope +is calculated continuously, by lowpass filtering the individual +channels of the NAP as they flow from the cochlea simulation. +.LP +The excitation pattern produced by genepn is intended to simulate the +spectral representation of a sound as it occurs in the peripheral +auditory system after neural transduction at about the level of the +cochlea nucleus. As a result, the frequency resolution of the +analysis varies with the center frequency of the channel, and the +distribution of channels across frequency is chosen to match that in +the auditory system. (For details, see the manual entry for genbmm.) +The excitaion pattern is a plot of the activity in each channel as a +function of the centre frequency of the auditory filter that defines +the channel. In AIM, the suffix 'epn' is used to distinguish this +spectral representation from the other spectral representations +provided by the software ('asa' auditory spectral analysis, 'sgm' +auditory spectrogram, and 'cgm' cochleogram). +.LP +The NAP generated by genepn is the same as that produced by gennap. +The primary differences are in the display defaults and the inclusion +of the Leaky Integration used to construct the excitation patterns +from the NAP. As a result, this manual entry is restricted to +describing the option values that differ from those in gennap and the +additional options required to control the Leaky Integration. +.LP +.SH DISPLAY DEFAULTS +.LP +The default values for three of the display options are reset to +produce a spectral format rather than a landscape. Specifically, +display=excitation, bottom=0 and top=2500. The number of channels is +increased to 128 to ensure reasonable frequency resolution in the +excitation pattern display. +.LP +.SH LEAKY INTEGRATION +.LP +.TP 13 +stages_idt +Number of stages of lowpass filtering +.RS +Default unit: scalar. Default value: 2 +.RE +.TP 13 +tup_idt +The time constant for each filter stage +.RS +Default unit: ms. Default value: 8 ms. +.RE +.LP +The Equivalent Rectandular Duration (ERD) of a two stage lowpass +filter is about 1.6 times the time constant of each stage, or +12.8 ms in the current case. +.TP 13 +frstep_epn +The time between successive spectral frames +.RS +Default unit: ms. Default value: 10 ms. +.RE +.LP +With a frstep_epn of 10 ms, genepn will produce +spectral frames at a rate of 100 per second. +.LP +.TP 13 +downsample +The time between successive spectral frames. +.RS +Default unit: ms. Default value: 10 ms. +.RE +.LP +Downsample is simply another name for frstep_epn, provided to +facilitate a different mode of thinking about time-series data. +.RE +.LP +.LP +.SH FILES +.LP +.TP 13 +.genepnrc +The options file for genepn. +.LP +.SH SEE ALSO +.LP +genasa, gennap, genbmm, gensgm, gencgm +.LP +.SH COPYRIGHT +.LP +Copyright (c) Applied Psychology Unit, Medical Research Council, 1995 +.LP +Permission to use, copy, modify, and distribute this software without fee +is hereby granted for research purposes, provided that this copyright +notice appears in all copies and in all supporting documentation, and that +the software is not redistributed for any fee (except for a nominal +shipping charge). Anyone wanting to incorporate all or part of this +software in a commercial product must obtain a license from the Medical +Research Council. +.LP +The MRC makes no representations about the suitability of this +software for any purpose. It is provided "as is" without express or +implied warranty. +.LP +THE MRC DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING +ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL +THE A.P.U. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES +OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, +WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, +ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS +SOFTWARE. +.LP +.SH ACKNOWLEDGEMENTS +.LP +The AIM software was developed for Unix workstations by John +Holdsworth and Mike Allerhand of the MRC APU, under the direction of +Roy Patterson. The physiological version of AIM was developed by +Christian Giguere. The options handler is by Paul Manson. The revised +SAI module is by Jay Datta. Michael Akeroyd extended the postscript +facilites and developed the xreview routine for auditory image +cartoons. +.LP +The project was supported by the MRC and grants from the U.K. Defense +Research Agency, Farnborough (Research Contract 2239); the EEC Esprit +BR Porgramme, Project ACTS (3207); and the U.K. Hearing Research Trust. +