title: A low cost, non-individualized surround sound system based upon head related transfer functions: an ergonomics study and prototype development.
abstract: This paper reports on the types and magnitudes of localization errors of simulated binaural direction cues generated using non-individualized, head-related transfer functions (HRTFs) with different levels of complexity. Four levels of complexity, as represented by the number of non-zero coefficients of the associated HRTF filters (128, 64, 32, 18 non-zero coefficients), were studied. Experiment 1 collected 1728 data runs that were exhaustive combinations of the four levels of complexity, nine simulated directions of sound (no direction (i.e., diotical-mono), 0 degrees , 45 degrees , 90 degrees , 135 degrees , 180 degrees , 225 degrees , 270 degrees , and 315 degrees azimuth angles at 0 degrees elevation), two repetitions, and 24 participants). Binaural cues generated from HRTFs of reduced complexity (from 128 to 18 non-zero coefficients) produced significantly higher localization errors for the directions of 45 degrees , 135 degrees , 225 degrees , and 315 degrees azimuth angles (p<0.01). From the directions of 0 degrees , 90 degrees , and 270 degrees azimuth angles, the cues produced by HRTFs with reduced complexity did not affect the localization error (p>0.2). Surprisingly, cues produced by HRTFs of 128 non-zero coefficients did not have the lowest number of errors. From 45 degrees , 135 degrees , 225 degrees , and 315 degrees , the lowest numbers of errors were obtained from cues produced by HRTFs of 64, 32, 32, and 64 non-zero coefficients, respectively. Based on these findings, a prototype virtual headphone-based surround-sound (VHSS) system was developed. A double-blind usability experiment with 32 participants indicated that the prototype VHSS system received significantly better surround-sound ratings than did a Dolby stereo system (p<0.02). This paper reports results from an original ergonomics study and the application of these results to the design of a consumer product.
authors.affiliation: Department of Industrial Engineering and Logistics Management, Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong SAR. rhyso@ust.hk
authors.forename: R H Y
authors.initials: RH
authors.lastname: So
authors.forename: N M
authors.initials: NM
authors.lastname: Leung
authors.forename: J
authors.initials: J
authors.lastname: Braasch
authors.forename: K L
authors.initials: KL
authors.lastname: Leung
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D000328:Adult; D000704:Analysis of Variance; D001307:Auditory Perception / Q000502:physiology*; D003463:Cues; D006804:Ergonomics; D005260:Female; D006257:Head / Q000502:physiology*; D006801:Humans; D008297:Male; D013017:Sound Localization / Q000502:physiology*; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires