AES San Francisco 2008
Poster Session P11
Friday, October 3, 2:30 pm — 4:00 pmP11 - Listening Tests & Psychoacoustics
P11-1 Testing Loudness Models—Real vs. Artificial Content—James Johnston, Neural Audio Corp. - Kirkland, WA, USA
A variety of loudness models have been recently proposed and tested by various means. In this paper some basic properties of loudness are examined, and a set of artificial signals are designed to test the "loudness space" based on principles dating back to Harvey Fletcher, or arguably to Wegel and Lane. Some of these signals, designed to model "typical" content, seem to reinforce the results of prior loudness model testing. Other signals, less typical of standard content, seem to show that there are some substantial differences when these less common signals and signal spectra are used.
Convention Paper 7564 (Purchase now)
P11-2 Audibility of High Q-factor All-Pass Components in Head-Related Transfer Functions—Daniela Toledo, Henrik Møller, Aalborg University - Aalborg, Denmark
Head-related transfer functions (HRTFs) can be decomposed into minimum phase, linear phase, and all-pass components. It is known that low Q-factor all-pass sections in HRTFs are audible as lateral shifts when the interaural group delay at low frequencies is above 30 µs. The goal of our investigation is to test the audibility of high Q-factor all-pass components in HRTFs and the perceptual consequences of removing them. A three-alternative forced choice experiment has been conducted. Results suggest that high Q-factor all-pass sections are audible when presented alone, but inaudible when presented with their minimum phase HRTF counterpart. It is concluded that high Q-factor all-pass sections can be discarded in HRTFs used for binaural synthesis.
Convention Paper 7565 (Purchase now)
P11-3 A Psychoacoustic Measurement and ABR for the Sound Signals in the Frequency Range between 10 kHz and 24 kHz—Mizuki Omata, Musashi Institute of Technology - Tokyo, Japan; Kaoru Ashihara, Advanced Industrial Science and Technology - Tsukuba, Japan; Motoki Koubori, Yoshitaka Moriya, Masaki Kyouso, Shogo Kiryu, Musashi Institute of Technology - Tokyo, Japan
In high definition audio media such as SACD and DVD-audio, wide frequency range far beyond 20 kHz is used. However, the auditory characteristics for the frequencies higher than 20 kHz have not been necessarily understood. At the first step to make clear the characteristics, we conducted a psychoacoustic and an auditory brain-stem response (ABR) measurement for the sound signals in the frequency range between 10 kHz and 24 kHz. At a frequency of 22 kHz, the hearing threshold in the psychoacoustic measurement could be measured for 4 of 5 subjects. The minimum sound pressure level was 80 dB. The thresholds of 100 dB in the ABR measurement could be measured for 1 of the 5 subjects.
Convention Paper 7566 (Purchase now)
P11-4 Quantifying the Strategy Taken by a Pair of Ensemble Hand-Clappers under the Influence of Delay—Nima Darabii, Peter Svensson, The Centre for Quantifiable Quality of Service in Communication Systems, NTNU - Trondheim, Norway; Snorre Farner, IRCAM - Paris, France
Pairs of subjects were placed in two acoustically isolated rooms clapping together under an influence of delay up to 68 ms. Their trials were recorded and analyzed based on a definition of compensation factor. This parameter was calculated from the recorded observations for both performers as a discrete function of time and thought of as a measure of the strategy taken by the subjects while clapping. The compensation factor was shown to have a strong individual as well as a fairly musical dependence. Increasing the delay compensation factor was shown obviously to be increased as it is needed to avoid tempo decrease for such high latencies. Virtual anechoic conditions cause a less deviation for this factor than the reverberant conditions. Slightly positive compensation parameter for very short latencies may lead to a tempo acceleration in accordance with Chafe effect.
Convention Paper 7567 (Purchase now)
P11-5 Quantitative and Qualitative Evaluations for TV Advertisements Relative to the Adjacent Programs—Eiichi Miyasaka, Akiko Kimura, Musashi Institute of Technology - Yokohama, Kanagawa, Japan
The sound levels of advertisements (CMs) in Japanese conventional terrestrial analog broadcasting (TAB) were quantitatively compared with those in Japanese terrestrial digital broadcasting (TDB). The results show that the average CM-sound level in TDB was about 2 dB lower and the average standard deviation was wider than those in TAB, while there were few differences between TAB and TDB at some TV station. Some CMs in TDB were perceived clearly louder than the adjacent programs although the sound level differences between the CMs and the programs were only within ±2 dB. Next, insertion methods of CMs into the main programs in Japan were qualitatively investigated. The results show that some kinds of the methods could unacceptably irritate viewers.
Convention Paper 7568 (Purchase now)