tomwalters@0: % method of class @signal
tomwalters@0: % function sig=ci_simulate(signal)
tomwalters@0: %
tomwalters@0: %   INPUT VALUES:
tomwalters@0: %       sig:      @signal
tomwalters@0: %
tomwalters@0: %   RETURN VALUE:
tomwalters@0: %       sigresult:  @signal `
tomwalters@0: %
bleeck@3: % This external file is included as part of the 'aim-mat' distribution package
bleeck@3: % (c) 2011, University of Southampton
bleeck@3: % Maintained by Stefan Bleeck (bleeck@gmail.com)
bleeck@3: % download of current version is on the soundsoftware site: 
bleeck@3: % http://code.soundsoftware.ac.uk/projects/aimmat
bleeck@3: % documentation and everything is on http://www.acousticscale.org
tomwalters@0: 
tomwalters@0: function sig=ci_simulate(sigorg)
tomwalters@0: % stolen from AMO.m
tomwalters@0: 
tomwalters@0: audio_sample_rate=getsr(sigorg);
tomwalters@0: % audio_sample_rate=16000;
tomwalters@0: 
tomwalters@0: p.channel_stim_rate=900;
tomwalters@0: p.audio_sample_rate=audio_sample_rate;
tomwalters@0: p.analysis_rate=p.channel_stim_rate;
tomwalters@0: p.num_selected = 10;
tomwalters@0: p.num_bands = 22;
tomwalters@0: p.electrodes=22:-1:1;
tomwalters@0: 
tomwalters@0: p=Append_process(p,'FFT_filterbank_proc');
tomwalters@0: p=Append_process(p,'Power_sum_envelope_proc');
tomwalters@0: p=Append_process(p,'Reject_smallest_proc');
tomwalters@0: 
tomwalters@0: values=getvalues(sigorg);
tomwalters@0: FTM=Process(p,values);
tomwalters@0: 
tomwalters@0: 
tomwalters@0: % Parameters for Resynthesis
tomwalters@0: % --------------------------
tomwalters@0: pre.resynthesis_rate = audio_sample_rate;
tomwalters@0: pre.num_bands = p.num_bands;
tomwalters@0: pre.analysis_rate = p.channel_stim_rate;
tomwalters@0: pre.electrodes=p.electrodes;
tomwalters@0: 
tomwalters@0: insertion = 22;                     % insertion depth in mm
tomwalters@0: cochlength=33;  % length of cochlea
tomwalters@0: elecspacing = 0.75;                                                             % spacing between electrodes in mm
tomwalters@0: b = 0.3;                             % space constant in mm
tomwalters@0: 
tomwalters@0: % prepare non-overlapping crossover frequencies according to Greenwood
tomwalters@0: % --------------------------------------------------------------------
tomwalters@0: for i=1:23
tomwalters@0:     %elec_position_base(i)=insertion-elecspacing*(i-1);                            % position of elec in cochlea from base [mm]
tomwalters@0:     crossover_position_base(i)=insertion - (elecspacing*(i-1) - elecspacing*0.5);  % position between electrodes from base [mm]
tomwalters@0: end
tomwalters@0: crossover_position_apex=cochlength-crossover_position_base';                        % position between electrodes from apex [mm]
tomwalters@0: crossover_freqs_greenwood=Greenwood_x2cf(crossover_position_apex);                  % corresponding Greenwood frequencies
tomwalters@0: % check if there are frequencies above 1/2 sampling rate,
tomwalters@0: % and remove those bands from FTM, electrodes and crossover freq table
tomwalters@0: toohigh=sum(crossover_freqs_greenwood>0.5*pre.resynthesis_rate);
tomwalters@0: crossover_freqs_greenwood=crossover_freqs_greenwood(1:end-toohigh);                 % only those < half the sampling rate
tomwalters@0: pre.electrodes=pre.electrodes(1:sum(p.electrodes>toohigh));
tomwalters@0: FTM=FTM(1:sum(p.electrodes>toohigh),:);
tomwalters@0: num_bands_after=length(pre.electrodes);
tomwalters@0: if pre.num_bands~=num_bands_after
tomwalters@0:     msgbox([num2str(pre.num_bands-num_bands_after) ' of the active basal electrodes correspond(s) to frequencies > half the sampling frequency and will be disabled.'],'Disabling electrodes','warn','modal');
tomwalters@0: end
tomwalters@0: pre.num_bands=num_bands_after;
tomwalters@0: 
tomwalters@0: % resynthesize
tomwalters@0: % ------------
tomwalters@0: %sinusoid
tomwalters@0: %     pre.resynthesis_carrier = 'sinus';
tomwalters@0: %     pre.crossover_freqs=crossover_freqs_greenwood;  % sinusoids following Greenwood
tomwalters@0: 
tomwalters@0: % noise                                   % NOISE
tomwalters@0:     pre.resynthesis_carrier = 'noise';  
tomwalters@0:     pre.crossover_freqs=crossover_freqs_greenwood;
tomwalters@0: 
tomwalters@0: pre = Resynthesis(pre);
tomwalters@0: simul = Resynthesis(pre,FTM);
tomwalters@0:        
tomwalters@0: %Windowing and zeropadding to remove clicks
tomwalters@0: w = risewindow(length(simul),0.01*pre.resynthesis_rate)';     %a 10 ms linear rise and fall
tomwalters@0: simul = [zeros(1,10) w.*simul zeros(1,10)];
tomwalters@0: 
tomwalters@0:     
tomwalters@0:     % return a signal:
tomwalters@0: sig=signal(simul,audio_sample_rate);
tomwalters@0: sig=setname(sig,'Convolution');
tomwalters@0: 
tomwalters@0: 
tomwalters@0: return;