The Journal of the Acoustical Society of Korea (한국음향학회지)

The Acoustical Society of Korea (한국음향학회)
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Numerical Simulation of Head Related Transfer Functions and Sound Fields

수치해석을 이용한 머리전달함수의 계산 및 음장해석

  • ;
  • V. Kahana (Southampton University) ;
  • P. A. Nelson (Southampton University) ;
  • M. Petyt (Southampton University)
  • 최성훈 (한국과학기술원 기계공학과) ;
  • ;
  • ;
  • Published : 2001.08.01
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Abstract

The goal of using numerical methods in this study is two-fold: to replicate a set of measured, individualized HRTFs by a computer simulation, and also to visualise the resultant sound field around the head. Two methods can be wed: the Boundary Element Method (BEM) and the Infinite-Finite Element Method (IFEM). This paper presents the results of a preliminary study carried out on a KEMAR dummy-head, the geometry of which was captured with a high accuracy 3-D laser scanner and digitiser. The scanned computer model was converted to a few valid BEM and IFEM meshes with different polygon resolutions, enabling us to optimise the simulation for different frequency ranges. The results show a good agreement between simulations and measurements of the sound pressure at the blocked ear-canal of the dummy-head. The principle of reciprocity provides an effect method to simulate HRTF database. The BEM was also used to investigate the total sound field around the head, providing a tool to visualise the sound field for different arrangements of virtual acoustic imaging systems.

수치해석 방법을 이용하여 실험으로 구한 머리전달함수 (Head Related Transfer Function: HRTF)를 컴퓨터 시뮬레이션으로 대치하고, 청취자의 머리 주변에서의 음장을 가시화하는 방법에 대해 다룬다. 본 논문에서는 경계요소법 (Boundary Element Method)과 무한요소법 (Infinite-Finite Element Method)의 두 가지 방법을 이용한다. 지금까지는 더미헤드 (Dummy-Head)등을 이용한 실험으로 머리전달함수를 구하였는데 이 실험에는 상당한 시간과 장비가 필요하다. 3차원 레이저스캐너를 이용하여 KEMAR 더미헤드의 형상을 측정하고 이것을 여러 다른 요소 수를 가지는 경계요소모델 및 무한요소모델로 변환하여 머리전달함수를 계산하고 모델의 요소 크기와 적용 가능한 주파수 대역과의 관계에 대해 분석한다. 측정을 통해 구한 머리전달함수와 비교하여 모델을 검증하고 음향학의 상반원리를 적용하여 머리전달함수의 데이터베이스를 구한다. 또한 몇 가지 가상음향 시스템에 대한 음장해석을 통해 주파수 및 시간영역에서의 음장을 가시화한다.

Keywords

References

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