PMID- 25235000
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20150519
LR  - 20140919
IS  - 1520-8524 (Electronic)
IS  - 0001-4966 (Linking)
VI  - 135
IP  - 4
DP  - 2014 Apr
TI  - Smoothing individual head-related transfer functions in the frequency and spatial 
      domains.
PG  - 2012-25
LID - 10.1121/1.4867372 [doi]
AB  - When re-synthesizing individual head related transfer functions (HRTFs) with a 
      microphone array, smoothing HRTFs spectrally and/or spatially prior to the 
      computation of appropriate microphone filters may improve the synthesis accuracy. 
      In this study, the limits of the associated HRTF modifications, until which no 
      perceptual degradations occur, are explored. First, complex spectral smoothing of 
      HRTFs into constant relative bandwidths was considered. As a prerequisite to 
      complex smoothing, the HRTF phase spectra were substituted by linear phases, 
      either for the whole frequency range or above a certain cut-off frequency only. 
      The results indicate that a broadband phase linearization of HRTFs can be 
      perceived for certain directions/subjects and that the thresholds can be 
      predicted by a simple model. HRTF phase spectra can be linearized above 1 kHz 
      without being detectable. After substituting the original phase by a linear phase 
      above 5 kHz, HRTFs may be smoothed complexly into constant relative bandwidths of 
      1/5 octave, without introducing noticeable artifacts. Second, spatially smoother 
      HRTF directivity patterns were obtained by levelling out spatial notches. It 
      turned out that spatial notches do not have to be retained if they are less than 
      29 dB below the maximum level in the directivity pattern.
FAU - Rasumow, Eugen
AU  - Rasumow E
AD  - Jade Hochschule, Institut fur Hortechnik und Audiologie, Ofener Strabetae 16-19, 
      26121 Oldenburg, Germany.
FAU - Blau, Matthias
AU  - Blau M
AD  - Jade Hochschule, Institut fur Hortechnik und Audiologie, Ofener Strabetae 16-19, 
      26121 Oldenburg, Germany.
FAU - Hansen, Martin
AU  - Hansen M
AD  - Jade Hochschule, Institut fur Hortechnik und Audiologie, Ofener Strabetae 16-19, 
      26121 Oldenburg, Germany.
FAU - van de Par, Steven
AU  - van de Par S
AD  - Universitat Oldenburg, Department fur Medizinische Physik und Akustik, 
      Exzellenzcluster Hearing4All, Carl-von-Ossietzky-Strabetae 11, 26129 Oldenburg, 
      Germany.
FAU - Doclo, Simon
AU  - Doclo S
AD  - Universitat Oldenburg, Department fur Medizinische Physik und Akustik, 
      Exzellenzcluster Hearing4All, Carl-von-Ossietzky-Strabetae 11, 26129 Oldenburg, 
      Germany.
FAU - Mellert, Volker
AU  - Mellert V
AD  - Universitat Oldenburg, Department fur Medizinische Physik und Akustik, 
      Exzellenzcluster Hearing4All, Carl-von-Ossietzky-Strabetae 11, 26129 Oldenburg, 
      Germany.
FAU - Puschel, Dirk
AU  - Puschel D
AD  - Akustik Technologie Gottingen, Bunsenstrabetae 9c, 37073 Gottingen, Germany.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Acoust Soc Am
JT  - The Journal of the Acoustical Society of America
JID - 7503051
EDAT- 2014/09/23 06:00
MHDA- 2014/09/23 06:01
CRDT- 2014/09/20 06:00
PHST- 2014/09/20 06:00 [entrez]
PHST- 2014/09/23 06:00 [pubmed]
PHST- 2014/09/23 06:01 [medline]
AID - 10.1121/1.4867372 [doi]
PST - ppublish
SO  - J Acoust Soc Am. 2014 Apr;135(4):2012-25. doi: 10.1121/1.4867372.