AES Munich 2009
Sunday, May 10, 13:00 — 16:00
Paper Session P28
P28 - Psychoacoustics and Perception
Chair: Florian Wickelmaier
P28-1 Localization of Consecutive Sound Events in Reverberant Environment—Marko Takanen, Antti Jylhä, Tapani Pihlajamäki, Juha Holm, Ilkka Huhtakallio, Ville Pulkki, Helsinki University of Technology - Espoo, Finland
A listening test was conducted to assess the localization of consecutive sound events in simulated reverberant conditions. The stimuli consisted of two sound events, which were reverberant wideband harmonic sounds reproduced in a multichannel anechoic chamber. Localization threshold for the latter sound event was measured as the direct-to-reverberant sound level ratio with an adaptive transformed up-down method. The studied factors affecting the localization threshold were the time interval and pitch difference between the two sound events and the time gap between the direct sound and reverberation. The results indicate that all factors have a significant effect on localization.
Convention Paper 7807 (Purchase now)
P28-2 The Contrasting and Conflicting Definitions of Envelopment—Jan Berg, Luleå University of Technology - Luleå, Sweden
In spatial audio, the term envelopment is not unambiguously defined and the different de facto definitions both overlap and contradict one another. This unclarity may pose a problem where the sensation of being surrounded by sound is subject for investigation and analysis. This paper reviews the different concepts of envelopment in order to point to where possible problems may occur. A tentative suggestion for a terminology that can serve the different contexts of enveloping sounds is also given.
Convention Paper 7808 (Purchase now)
P28-3 Apparent Source Width in ITU Surround—Jorge Medina Victoria, Thomas Görne, Hamburg University of Applied Sciences - Hamburg, Germany
Apparent Source Widths (ASW) of phantom images in a ITU-R BS.775-1 standard surround loudspeaker configuration have been investigated for different signals by means of a randomized blind test. Test signals were generated from anechoic recordings by amplitude panning between adjacent channels. The listening test showed that an increase of Apparent Source Width coincides with the increase of localization uncertainty at the side and back areas of the ITU setup. Largest ASW values were found between RS and LS channels.
Convention Paper 7809 (Purchase now)
P28-4 A New Methodological Approach to the Noise Threat Evaluation Based on the Selected Physiological Properties of the Human Hearing System—Jozef Kotus, Bozena Kostek, Andrzej Czyzewski, Gdansk University of Technology - Gdansk, Poland
A new way of assessment of noise-induced harmful effects on the human hearing system is presented in this paper. The method takes into consideration properties of the selected physiological human hearing system. On the basis of the hearing examinations and noise measurements results and psychoacoustical noise dosimeter performance the new indicators of the noise harmfulness were proposed. The evaluation of the proposed indicators were conducted on the basis of hearing examinations in the real noise exposure situations and also on the basis of the simulation results using standard test signals (such as white, pink, and brown noise). The performed analysis and obtained results confirmed the practical usefulness and correctness of the proposed indicators.
Convention Paper 7813 (Purchase now)
P28-5 Octave-Band Analysis on ITU-R Listening Test Data—Ian M. Dash, Australian Broadcasting Corporation - Sydney, NSW, Australia
Listening test data collected in 2003 on 49 audio program samples were used to formulate the ITU-R BS.1770 program loudness prediction algorithm. The validity of this data at low frequencies was unproven. Octave-band analysis has therefore been performed on the test samples to test for audibility in each band. Results suggest that further listening tests may be needed to obtain reliable low-frequency data. A multiple regression analysis was also performed on the octave-band data to obtain a least-squares weighting curve for comparison with the BS.1770/RLB2 weighting curve. Results suggest that while the BS.1770 curve performs well, there is still room for improvement.
Convention Paper 7811 (Purchase now)
P28-6 Windowed Sine Bursts: In Search of Optimal Test Signals for Detecting the Threshold of Audibility of Temporal Decays—Andrew Goldberg, Helsinki University of Technology - Espoo, Finland
A slow decay in an audio signal is perceived as ringing and is commonly caused by room modes. This affects the perception of intelligibility, clarity, definition, and spatial rendering. A method has previously been devised to find the threshold of audibility of the decay in low-frequency narrow-band signals. One of the test signals in the large-scale listening test will be a low-frequency sine burst, but spectral spreading at the start and end of the test signal acts as an additional non-modal cue. This effect is removed by windowing, for example a half Hann. The aim of this paper is to determine the window length required (threshold) to render the end of the test signal free from audible spectral spreading. The Parameter Estimation by Sequential Testing (PEST) method and calibrated headphones (to remove factors associated with the listening environment) are used in subjective listening tests. The window length threshold is found to be constant above 200 Hz but rises exponentially toward low frequencies, and is replay level dependent. Threshold may be related to the absolute threshold of hearing, masking curves and/or auditory filter bandwidth.
Convention Paper 7812 (Purchase now)