THE AUDITORY MODELING TOOLBOX

Applies to version: 0.9.8

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BAUMGARTNER2013 - Model for sound localization in sagittal planes

Usage

pmv = baumgartner2013( target,template )
[pmv,respang,tang] = baumgartner2013(target,template,u,lat,flow,fhigh,stim,fsstim,polsamp)

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 listener-specific template. Options 1 & 2 equivalent to target

Output parameters

pmv predicted probability mass vectors for response angles with respect to target positions. 1st dim: response angle. 2nd dim: target angle.
respang polar response angles (after regularization of angular sampling)
tang polar target angles in the given sagittal plane

baumgartner2013(...) is a model for sound-source localization in sagittal planes (SPs). It bases on the comparison of internal sound representation with a template and results in a probabilistic prediction of polar angle response.

baumgartner2013 accepts the following key/value pairs:

'fs',fs Define the sampling rate of the impulse responses. Default value is 48000 Hz.
'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.
'lat',lat Set the perceived lateral angle of the target sound to lat. Default value is 0 deg (midsagittal plane).
'u',u Set the listener-specific uncertainty (standard deviation of the Gaussian transformation from the distance metric of the comparison process to the similarity index) to u. Default value is 2 dB.
'space',s Set spacing of auditory filter bands to s numbers of equivalent rectangular bandwidths (ERBs). Default value is 1 ERB.
'bwsteep',bws Set the steepness factor bws of the sigmoid function applied for binaural weighting of monaural similarity indices. Default value is 13 deg.
'polsamp',ps Define the the polar angular sampling of the current SP. As default the sampling of ARI's HRTF format along the midsagittal plane is used, i.e., \(ps = [-30:5:70,80,100,110:5:210]\) .

baumgartner2013 accepts the following flags:

'gammatone' Use the Gammatone filterbank for peripheral processing. This is the default.
'langendijk2002_spectralanalysis'
 Use a filterbank approximation based on DFT with constant relative bandwidth for peripheral processing. This was used by Langendijk and Bronkhorst (2002).
'ihc' Incorporate the transduction model of inner hair cells used by Dau et al. (1996). This is the default.
'noihc' Do not incorporate the IHC stage.
'regular' Apply spline interpolation in order to regularize the angular sampling of the polar response angle. This is the default.
'noregular' Disable regularization of angular sampling.

Requirements:

  1. SOFA API from http://sourceforge.net/projects/sofacoustics for Matlab (in e.g. thirdparty/SOFA)
  2. Data in hrtf/baumgartner2013

References:

P. Majdak, R. Baumgartner, and B. Laback. Acoustic and non-acoustic factors in modeling listener-specific performance of sagittal-plane sound localization. Front Psychol, 5(319):pages not available yet, doi:10.3389/fpsyg.2014.00319, 2014. [ DOI ]

R. Baumgartner. Modeling sagittal-plane sound localization with the application to subband-encoded head related transfer functions. Master's thesis, University of Music and Performing Arts, Graz, June 2012. [ .pdf ]

R. Baumgartner, P. Majdak, and B. Laback. Assessment of Sagittal-Plane Sound Localization Performance in Spatial-Audio Applications, chapter 4, pages 93-119. Springer-Verlag GmbH, 2013.

T. Dau, D. Pueschel, and A. Kohlrausch. A quantitative model of the effective signal processing in the auditory system. I. Model structure. J. Acoust. Soc. Am., 99(6):3615-3622, 1996a.

E. Langendijk and A. Bronkhorst. Contribution of spectral cues to human sound localization. J. Acoust. Soc. Am., 112:1583-1596, 2002.

R. Patterson, I. Nimmo-Smith, J. Holdsworth, and P. Rice. An efficient auditory filterbank based on the gammatone function. APU report, 2341, 1987.