function [t,table]=absolutethreshold(freq,varargin)
%ABSOLUTETHRESHOLD  Absolute threshold at specified frequencies
%   Usage:  t=absolutethreshold(freq);
%           t=absolutethreshold(freq,...);
%
%   `absolutethreshold(freq)` will return the absolute threshold of hearing
%   in dB SPL at the frequencies given in *freq*. The output will have the
%   same shape as the input.
%
%   `[outvals,table]=absolutethreshold(...)` additionally returns the
%   frequencies table defining the choosen standard. The first column of
%   the table contains frequencies in Hz, and the second column contains the
%   absolute threshold at the given frequency.
%
%   `absolutethreshold` takes the following optional parameters:
%
%     'iso226_2003'  Free field binaural as given by the ISO 226:2003
%                    standard.
%
%     'iso389_2005'  Diffuse field binaural as given by the ISO 389-7:2005
%                    standard.
%
%     'map'          The ISO 226:2003 standard coverted to minimal
%                    audible pressure using the method from Bentler &
%                    Pavlovic 1989.
%
%     'er3a'         Using ER-3A insert earphones. This is described in
%                    the ISO 389-2:1994(E) standard
%
%     'er2a'         Using ER-2A insert earphones. This is described in
%                    Han & Poulsen (1998)
%
%     'hda200'       Using HDA200 circumaural earphone. This is
%                    decribed in the ISO 389-8:2004 standard.
%
%   Absolute thresholds for the ER2A and HDA-200 are provided up to 16
%   kHz by the ISO 389-5:2006 standard.
%
%   The default is to use the `'iso226_2003'` setting.
%
%   Demos: demo_absolutethreshold
%
%   References: iso226-2003 iso389-2-1994 iso389-5-2006 iso389-8-2004 bentler1989transfer han1998equivalent
  
% AUTHOR : Peter Søndergaard based on data collected by Claus Elberling
  
if nargin<1
  error('Too few input parameters.');
end;

definput.import = {'absolutethreshold'};
definput.importdefaults = {'iso226_2003'};

[flags,kv,table]  = ltfatarghelper({'table'},definput,varargin);

t=spline(table(:,1),table(:,2),freq);