# THE AUDITORY MODELING TOOLBOX

Applies to version: 1.1.0

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# BAUMGARTNER2017 - Sound externalization model based on monaural spectral cues

## Usage

[E,cues,cueLabels] = baumgartner2017( target,template )


## Input parameters

 target binaural impulse response(s) referring to the directional transfer function(s) (DFTs) of the target sound(s). Option 1: given in SOFA format -> sagittal plane DTFs will be extracted internally. Option 2: binaural impulse responses of all available listener-specific DTFs of the sagittal plane formatted according to the following matrix dimensions: time x direction x channel/ear template binaural impulse responses of all available listener-specific DTFs of the sagittal plane referring to the perceived lateral angle of the target sound. Options 1 & 2 equivalent to target.

## Output parameters

 E predicted degree of externalization cues outcomes of individual cues cueLabels cue labels; cell array with 1st col. denoting acronyms and 2nd col. for descriptions

## Description

baumgartner2017(...) is a model for sound externalization. It bases on the comparison of the intra-aural internal representation of the incoming sound with a template and results in a probabilistic prediction of polar angle response.

baumgartner2017 accepts the following optional parameters:

 'cueWeights',cW Set the weights of individual cues to determine the final externalization score. Cue-specific weights (entered as a vector) are ordered as follows: monaural spectral similarity (c.f., Baumgartner et al., 2014). This is the default. interaural spectral similarity of ILDs (c.f., Hassager et al., 2016) spectral standard deviation of ILDs (c.f., Georganti et al., 2013) temporal standard deviation of ILDs (c.f., Catic et al., 2015) interaural coherence (c.f., Hassager et al., 2017) interaural broadband time-intensity coherence difference in sound pressure level 'fs',fs Define the sampling rate of the impulse responses. Default value is 48000 Hz. 'S',S Set the listener-specific sensitivity threshold (threshold of the sigmoid link function representing the psychometric link between transformation from the distance metric and similarity index) to S. Default value is 1. 'lat',lat Set the apparent lateral angle of the target sound to lat. Default value is 0 degree (median SP). 'stim',stim Define the stimulus (source signal without directional features). As default an impulse is used. 'fsstim',fss Define the sampling rate of the stimulus. Default value is 48000 Hz. 'flow',flow Set the lowest frequency in the filterbank to flow. Default value is 700 Hz. 'fhigh',fhigh Set the highest frequency in the filterbank to fhigh. Default value is 18000 Hz. 'space',sp Set spacing of auditory filter bands (i.e., distance between neighbouring bands) to sp in number of equivalent rectangular bandwidths (ERBs). Default value is 1 ERB. 'do',do Set the differential order of the spectral gradient extraction to do. Default value is 1 and includes restriction to positive gradients inspired by cat DCN functionality. 'bwcoef',bwc Set the binaural weighting coefficient bwc. Default value is 13 degrees. 'range',c1 Set the range factor of the externalization scores to c1. Default value is 3.78 from Hassager et al. (2016). 'offset',c2 Set the offset of the externalization score to c2. Default value is 1 from Hassager et al. (2016). 'ILD_JND',L Set the just noticeable ILD difference to L from the internal template. Default value is 1 (dB). 'ITD_JND',T Set the just noticeable ITD difference to T from the internal template. Default value is 20e-6 (s).

## Requirements:

1. SOFA API from http://sourceforge.net/projects/sofacoustics for Matlab (in e.g. thirdparty/SOFA)
2. Data in hrtf/baumgartner2017
3. Circular Statistics Toolbox from https://de.mathworks.com/matlabcentral/fileexchange/10676-circular-statistics-toolbox-directional-statistics

## References:

R. Baumgartner, P. Majdak, H. Colburn, and B. Shinn-Cunningham. Modeling sound externalization based on listener-specific spectral cues. In Acoustics ‘17 Boston: The 3rd Joint Meeting of the Acoustical Society of America and the European Acoustics Association, Boston, MA, Jun 2017. [ DOI ]