Applies to version: 0.10.0

View the code

Go to function

BAUMGARTNER2020 - Model for sound externalization


[E,cues,cueLabels] = baumgartner2020( 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 formated 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 column for descriptions

baumgartner2019(...) 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.

baumgartner2020 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:

  1. monaural spectral similarity (MSS)
  2. interaural spectral similarity of ILDs (ISS)
  3. spectral standard deviation of monaural gradients (MSSD)
  4. spectral standard deviation of ILDs (ISSD)
  5. interaural broadband time-intensity coherence (ITIT)
  6. interaural coherence (IC)
  7. monaural intensity difference (MI)
  8. temporal standard deviation of ILDs (ITSD).

Default weights are 0.67 for MSS, 0.33 for ITIT, and 0 for all others.

'S',S : Set the cue-specific sensitivity parameter to S.
1/S represents the slope of sigmoidal mapping function. Vector order equivalent to cueWeights. Default values are determined by the weighted average sensitivities determined in Baumgartner and Majdak (2020) - run exp_baumgartner2020('tab2') to show them.
'lat',lat : Set the apparent lateral angle of the target sound to lat.
Default value is 0 degree (median SP).
'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).

baumgartner2020 accepts the following flags:

'LTA' : Looser-takes-all strategy: Model selects minimal
predicted externalization scores across cues with weights larger than zero.


  1. SOFA API from for Matlab (in e.g. thirdparty/SOFA)
  2. Data in hrtf/baumgartner2017
  3. Circular Statistics Toolbox from


R. Baumgartner and P. Majdak. Decision making in auditory externalization perception. bioRxiv, 2020. [ DOI ]