[crosscorr,t] = lindemann1986(insig,fs,c_s,w_f,M_f,T_int,N_1) [crosscorr,t] = lindemann1986(insig,fs,c_s,w_f,M_f,T_int) [crosscorr,t] = lindemann1986(insig,fs,c_s,w_f,M_f) [crosscorr,t] = lindemann1986(insig,fs,c_s,w_f) [crosscorr,t] = lindemann1986(insig,fs,c_s) [crosscorr,t] = lindemann1986(insig,fs)
|insig||binaural signal for which the cross-correlation should be calculated|
|fs||sampling rate (Hz)|
|crosscorr||A matrix containing the cross-correlation signal for every frequency channel fc and every time step n. The format of this matrix is output(n,m,fc), where m denotes the correlation (delay line) time step.|
|t||time axis for the time steps n in crosscorr|
|ild||interaural level difference (ILD) for every freqeuncy channel fc|
|cfreq||center frequencies of every frequency channel|
lindemann1986(insig,fs) calculates a binaural activity map for the given insig using a cross-correlation (delay-line) mechanism. The calculation is done for every frequency band in the range 5-40 Erb.
Lindemann has extended the delay line model of Jeffres (1948) by a contralateral inhibition, which introduce the ILD to the model. Also monaural detectors were extended, to handle monaural signals (and some stimuli with a split off of the lateralization image). Hess has extended the output from the Lindemann model to a binaural activity map dependent on time, by using a running cross-correlation function. This has been done here by starting a new running cross-correlation every time step T_int. A detailed description of these cross- correlation steps is given in the lindemann1986_bincorr function.
The steps of the binaural model to calculate the result are the following:
You may supply any flags or key/value pairs of the auditoryfilterbank, ihcenvelope or lindemann1986_bincorr at the end of the line of input arguments.
This example shows how to the binaural activity map for one frequency channel of the Lindemann binaural model for a sinusoid with a binaural modulation rate of 2 Hz.
fs = 44100; % Sampling rate f = 500; % Frequency of the sinusoid mf = 2; % Binaural modulation frequency % Generate 1~s binaural modulated sinusoid sig = sig_lindemann1986(f,mf,fs); % Model parameter (Note: T_int (ms) should be a multiple of 1000/f == 2) % Begin of the storage of the cross-correlation is set to 1, because we have a % non-stationary signal % Calculate binaural cross-correlation [cc,t] = lindemann1986(sig,fs,'T_int',6); % Plot frequency channel 11, due to round(freqtoerb(500))==11 plot_lindemann1986(cc,t,'fc',f);
W. Gaik. Combined evaluation of interaural time and intensity differences: Psychoacoustic results and computer modeling. J. Acoust. Soc. Am., 94:98--110, 1993.
W. Hess. Time-Variant Binaural-Activity Characteristics as Indicator of Auditory Spatial Attributes. PhD thesis, Ruhr-Universitaet Bochum, 2007.
L. Jeffress. A place theory of sound localization. Journal of comparative and physiological psychology, 41(1):35--39, 1948.
W. Lindemann. Extension of a binaural cross-correlation model by contralateral inhibition. I. Simulation of lateralization for stationary signals. J. Acoust. Soc. Am., 80:1608--1622, 1986.
W. Lindemann. Extension of a binaural cross-correlation model by contralateral inhibition. II. The law of the first wave front. J. Acoust. Soc. Am., 80:1623--1630, 1986.