AES Amsterdam 2008: Poster Session P20

P20 - Psychoacoustics, Perception, and Listening Tests

Monday, May 19, 14:00 — 15:30
P20-1 Loss of Subjective Localization Cues in Virtual Acoustic Opening—Elena Blanco-Martín, Francisco Javier Casajus-Quiros, Juan Jose Gomez-Alfageme, L. I. Ortiz-Berenguer, Universidad Politécnica de Madrid - Madrid, Spain
The reproduced sound event quality is very important in a WFS configuration that is used for an acoustic opening. One way of checking the subjective quality perceived by a listener is the ITU R. BS.1387 “Method for objective measurements of perceived audio quality,” but this method does not provide information about the listener’s ability to localize the sound. A Matlab application has been implemented (SEL, Sound Event Localization) simulating an acoustic opening configuration. The number of microphones and loudspeakers in the arrays is selectable, just as the sound source position, the gap between array transducers and the listener position. This simulation has been verified against a real configuration of acoustic opening. Moreover, the loss of localization cues has been analyzed with different multichannel codifications.
Convention Paper 7443 (Purchase now)

P20-2 Effect of Interaural Differences on Loudness of Narrowband Noise Bursts—Toni Hirvonen, Ville Pulkki, Helsinki University of Technology - Espoo, Finland
This paper investigates the effects of interaural time and level differences (ITDs and ILDs, respectively) on loudness. Dichotic samples containing various amounts of interaural differences were compared to a diotic reference. The subjects adjusted the relative threshold gain of the test sample using a two-alternative, forced choice adaptive procedure (2AFC). The test signals were Gaussian noise samples with a bandwidth of one critical band and center frequencies of 150, 600, and 2400 Hz. The results imply that ILD is prominently responsible for changes in directional loudness, which is in agreement with present binaural loudness models that consider only ILD. The experiments revealed significant individual differences between subjects even when matching two identical signals.
Convention Paper 7444 (Purchase now)

P20-3 Perception of Movements of a Focused Sound Generated with a Linear Loudspeaker Array System—Ichiki Manon, Daiki Sato, Tomoaki Tanno, Musashi Institute of Technology - Setagaya-ku, Tokyo, Japan; Kaoru Ashihara, National Institute of Advanced Science and Technology - Tsukuba, Japan; Shogo Kiryu, Musashi Institute of Technology - Setagaya-ku, Tokyo, Japan
A special loudspeaker array system was developed for an experiment on perception of movements of a focused sound. The spatial patterns of the sound pressure level for the focused sounds were measured. The patterns were improved compared to the previous preliminary experiment using commercial devices. A psychoacoustic experiment on perception of movements of the focused sound was conducted using the developed system.
Convention Paper 7445 (Purchase now)

P20-4 Subjective Evaluation for Music Recording Positions in a Coherent Region of a Reverberant Field—Yoshifumi Hara, Kogakuin University - Shinjuku-ku, Tokyo, Japan; Hiroaki Nomura, Kure College of Technology - Kure-city, Hiroshima, Japan; Mikio Tohyama, Waseda University - Shinjuku, Tokyo, Japan; Kazunori Miyoshi, Kogakuin University - Shinjuku-ku, Tokyo, Japan
In this paper we describe the most preferable frequency characteristics of the early reflections for music recording positions. We recorded short passages from two music pieces (Haendel,”Water Music Suite” and Brahms, ”Symphony No. 4”) at various distances from a sound source in a coherent region in a reverberation chamber. Subjects evaluated the preference and the subjective loudness through headphones under the diotic condition by paired comparison tests. As a result, we found that the most preferable distance indicated the distance where the loudness became maximum. The preferable recording condition could be also characterized by narrow-band envelope spectrum analysis.
Convention Paper 7446 (Purchase now)

P20-5 Efficient Individualization of HRTF Using Critical-Band-Based Spectral Cues Control—Yoomi Hur, Yonsei University - Seoul, Korea; Young-cheol Park, Yonsei University - Wonju, Korea; Dae Hee Youn, Yonsei University - Seoul, Korea; Seok-Pil Lee, Korea Electronics Technology Institute - Bundang-Gu, Sungnam-Si, Korea
Recently, 3-D audio technologies have been commonly implemented through headphones. A major problem of the headphone-based 3-D audio is in-the-head localization, which occurs due to the inaccurate Head-Related Transfer Function (HRTF). Since the individual measurements of HRTFs are impractical, there have been several researches for HRTF customization. In this paper we propose an efficient method of customizing HRTFs. In the proposed method, spectral notches and envelopes are controlled based on a critical-band rate. Thus, the structure of the proposed algorithm is much simpler than that of previous methods, but still effective. The proposed method was evaluated in the problem of externalization, and the results showed that the customized HRTF using the proposed method could greatly improve the externalization performance.
Convention Paper 7447 (Purchase now)

P20-6 How to Widen the Sweet Spot in Monitoring 5.1—Julien Bassères, Patrick Thevenot, Taylor Made System - Nangis, France
Generally speaking, sound reproduction tends to achieve the widest sweet spot. But it's seldom realized and more than that, the restricted sweet spot has become rather usual and well accepted by the audio community. This paper proposes to find a new approach in order to get a wider sweet spot, up to a certain extent, in multichannel. By optimizing the directivity of each loudspeaker in order to compensate the position of the listener, this method aims at creating a coherent and homogeneous acoustic field. Special care will be given to the directivity pattern (amplitude and phase) of the loudspeaker system.
Convention Paper 7448 (Purchase now)

P20-7 Auditory Modeling via Frequency Warped Transforms—Alexey Petrovsky, Belarusian State University of Informatics and Radioelectronics - Minsk, Belarus; Marek Parfieniuk, Adam Borowicz, Bialystok Technical University - Bialystok, Poland; Alexander Petrovsky, Belarusian State University of Informatics and Radioelectronics - Minsk, Belarus, and Bialystok Technical University, Bialystok, Poland
The goal of this paper is to show and compare four different versions of auditory modeling based on frequency warped transforms: bark-scaled wavelet packet decomposition, bark-scaled adapted wavelet packet decomposition, warped discrete Fourier transform, and four-band wavelets paraunitary filter bank, useful for perceptual audio coding, speech enhancement, and parametric audio coding matching pursuit procedure based on the psychoacoustic optimized wavelet packet dictionary. A practical implementation of the audio signal processing based on the given auditory modeling approaches are in details considered and analyzed from positions: depth of a compression, perceptual perception, a structural realizability, an opportunity to build embedded systems.
Convention Paper 7449 (Purchase now)

P20-8 The Role of Spectral Features in Sound Localization—Daniela Toledo, Henrik Møller, Aalborg University - Aalborg, Denmark
Spectral components of head-related transfer functions (HRTFs) are highly dependent on the anthropometric characteristics of subjects. In the low frequency range, a common structure is often found in HRTFs from different subjects. However, individual differences are seen at high frequencies. In binaural synthesis with non-individual HRTFs, localization errors occur if the spectral characteristics of the directional filters used do not match the individual characteristic of the listener. This investigation is focused on the spectral characteristics of HRTFs that are relevant as localization cues and how to parameterize them. This is done by cross-matching individual and non-individual HRTFs from different subjects according to the results of localization experiments.
Convention Paper 7450 (Purchase now)

P20-9 Multichannel Loudness Listening Test—Ian Dash, Australian Broadcasting Corporation - Sydney, NSW, Australia; Luis Miranda, Densil Cabrera, University of Sydney - Sydney, NSW, Australia
As part of ongoing research for ITU Recommendation BS.1770 Algorithms to measure audio programme loudness and true-peak audio level, listening tests were conducted using a standard five-channel geometry in a standard listening room to confirm the channel gains and the spectral weightings for equal loudness contribution. Most ITU-related work to date has used broadcast program as a test signal. In this test, octave band noise was used as a test signal. Twenty-seven listeners participated. Results were analyzed for statistical consistency as well as for average and variance. Agreement between the test results and various broadband loudness models, including ITU-R BS.1770, is examined.
Convention Paper 7451 (Purchase now)

Last Updated: 20080612, tendeloo

AES Amsterdam 2008Poster Session P20

AES Amsterdam 2008
Poster Session P20