120th AES Convention - Paris, France - Dates: Saturday May 20 - Tuesday May 23, 2006 - Porte de Versailles

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AES Paris 2006

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Last Updated: 20060404, mei

P29 - Posters: Psychoacoustics, Perception, and Listening Tests

Tuesday, May 23, 14:00 — 15:30

P29-1 Designing a Spatial Audio Attribute Listener Training System for Optimal TransferRafael Kassier, Tim Brookes, Francis Rumsey, University of Surrey - Guildford, Surrey, UK
Interest in spatial audio has increased due to the availability of multichannel reproduction systems for the home and car. Various timbral ear training systems have been presented, but relatively little work has been carried out into training in spatial audio attributes of reproduced sound. To demonstrate that such a training system is truly useful, it is necessary to show that learned skills are transferable to different settings. Issues relating to the transfer of training are examined; a recent study conducted by the authors is discussed in relation to the level of transfer shown by participants, and a new study is proposed that is aimed to optimize the transfer of training to different environments.

[Poster Presentation Associated with Paper Presentation P24-4]
Convention Paper 6819 (Purchase now)

P29-2 Evaluation of Loudness in a Room Acoustic ModelYi Shen, Konstantinos Angelakis, Technical University of Denmark - Kgs. Lyngby, Denmark
The equal loudness contours were measured using an analytical model, which was constructed for rectangular rooms based on the Kuttruff’s room acoustic model. A stimulus can be presented through the room acoustic model to the subjects via headphones. The results are in very close agreement with measurements in a real room. Two additional experiments were conducted to study the loudness as a function of reverberation time for different types of stimuli. The results showed that the effect of reverberation on loudness is negligible for a stationary stimulus. On the other hand, for an impulse train, loudness depends on both the reverberation time of the test room and the repetition frequency of the stimulus.

[Poster Presentation Associated with Paper Presentation P24-5]
Convention Paper 6820 (Purchase now)

P29-3 Investigations in Real-time Loudness MeteringGilbert Soulodre, Michel Lavoie, Communications Research Centre - Ottawa, Ontario, Canada
There has been much research in the past few years on loudness perception and metering. Recently, the authors developed an objective loudness algorithm that accurately measures the perceived loudness of mono, stereo, and multichannel audio sequences. The algorithm provides a single loudness reading for the overall audio sequence. In broadcast, film, and music applications it is desirable to have a real-time loudness meter that can track the loudness of the audio signal over time. The new meter would be used in conjunction with existing metering methods to provide additional information about the audio signal. In the present paper the requirements for such a meter are examined and new subjective testing methods are devised to help in the development and evaluation of a new meter.

[Poster Presentation Associated with Paper Presentation P24-7]
Convention Paper 6822 (Purchase now)

P29-4 Measuring the Threshold of Audibility of Temporal DecaysAndrew Goldberg, Genelec Oy - Iisalmi, Finland; Helsinki University of Technology, Espoo, Finland
A listening test system designed to measure the threshold of audibility of the decay time of low frequency resonances is described. The system employs the Parameter Estimation by Sequential Testing (PEST) technique, and the listening test is conducted on calibrated headphones to remove factors associated with the listening environment. Program signal, replay level, and resonance frequency are believed to influence decay time threshold. A trial the listening test shows that the system reveals realistic results but the temporal resonance modeling filter requires some adjustment to remove audible nonmodal cues. Transducer limitations still affect the test at low frequencies and high replay levels. Factors for future large-scale listening tests are refined. Early indications are that temporal decay thresholds rise with reduced frequency and SPL.

[Poster Presentation Associated with Paper Presentation P24-8]
Convention Paper 6823 (Purchase now)

P29-5 The Influence of Impulse Response Length and Transition Bandwidth of Magnitude Complementary Crossover on Perceived Sound QualityIva Djukic, Institute Mihailo Pupin - Belgrade, Serbia and Montenegro; Dejan Todorovic, RTS-Radio Beograd - Belgrade, Serbia and Montenegro; Ljiljana D. Milic, Institute Mihailo Pupin - Belgrade, Serbia and Montenegro
In this paper a special type of magnitude complementary IIR filter pair with variable transition bandwidth and impulse response length was used in order to examine the effects of these two characteristics on subjective perception of the reproduced sound. Two types of listening tests were performed. In the first type of tests the sum of crossover outputs was compared to the original signal. In the second type of tests the IIR filter pairs were compared among themselves, as well with linear phase magnitude complementary FIR filter pairs as a reference. The results of the tests show that overall differences are not significant. It was found that considered filters are suitable for loudspeaker crossover applications.

[Poster Presentation Associated with Paper Presentation P24-9]
Convention Paper 6824 (Purchase now)

P29-6 A System for Rapid Measurement and Direct Customization of Head-Related ImpulseSimone Fontana, Ecole Nationale Supérieure des Télécommuications - Paris, France; Angelo Farina, Università di Parma - Parma, Italy; Yves Grenier, Ecole Nationale Supérieure des Télécommuications - Paris, France
Head-Related Impulse Responses (HRIRs) measurement systems are quite complex and present long acquisition times for an accurate sampling of the full 3-D space. Therefore HRIRs customization has become an important research topic. In HRIRs customization some parameters (generally anthropometric measurements) are obtained from new listeners and ad-hoc HRIRs can be retrieved from them. Another way to get new listeners’ parameters is to measure a subset of the full 3-D space HRIRs and extrapolate them in order to obtain a full 3-D database. This partial acquisition system, of course, should be rapid and accurate. In this paper we present a system that allows for rapid acquisition and equalization of HRIRs for a subset of the 3-D grid. Then a technique to carry out HRIR customization based on the measured HRIRs will be described.
Convention Paper 6851 (Purchase now)

P29-7 Observations on Bimodal Audio Visual Subjective Assessments of a Virtual 3-D SceneUlrich Reiter, Sebastian Großmann, Dominik Strohmeier, Markus Exner, Technische Universität Ilmenau - Ilmenau, Germany
This paper deals with observations made during audio visual subjective assessments of perceived overall quality of a virtual 3-D scene. Over 30 test subjects were individually presented with a virtual living room. For each of them a predefined sequence of self-movement was displayed on a 2.7-m wide projection screen. The visual impression was complemented with different versions of room acoustic real time simulations rendered audible via a circular 8-channel loudspeaker setup. These were contrasted in a pair-comparison test. Interestingly, the amount of reverberation judged by test subjects to be “most realistic” was highly dependent on the acoustic stimulus itself. We will present a number of interesting observations related to expectations of test subjects and gender, as well as an interpretation from which we can derive a number of suggestions for subsequent bimodal assessments.
Convention Paper 6852 (Purchase now)

P29-8 Measurement of Reverberation Discrimination Threshold for Chinese Subjects with Chinese Music MotifsZihou Meng, Fengjie Zhao, Communication University of China - Beijing, China
The just-noticeable difference of reverberation time for Chinese subjects was studied using the Chinese music motifs as the test materials. Three subject groups were tested—the audio technician group, the students from the audio engineering department, and a group of students without professional training on audio engineering and listening. The test was carried out with headphones in mono style to get the intrinsic reverberation perception. The psychometric method is constant-stimulus-method. The measured just-noticeable difference of reverberation is higher than that reported in the study with western subjects and western music. The difference caused by different music motifs is insignificant, but the difference possibly caused by the professional training and experience of different subjects groups is noticeable.
Convention Paper 6853 (Purchase now)

P29-9 An Auditory Process Model for the Evaluation of Virtual Acoustic Imaging SystemsMunhum Park, Philip A. Nelson, University of Southampton - Southampton, UK; Youngtae Kim, Samsung Advanced Institute of Technology (SAIT) - Yongin-Si Gyeonggi-do, Korea
This paper describes the initial application of an auditory process model to the evaluation of various virtual acoustic imaging systems. The model has been designed to simulate human binaural hearing by means of an equalization-cancellation process for the binaural process and a template-matching with frequency weighting for the central process, while linear and nonlinear filters have been employed for the peripheral process. The model prediction has been shown to be consistent with the performance of human spatial hearing in case of localization of white Gaussian noise and the lateralization of low-frequency pure tones. In this paper virtual acoustic images presented by conventional stereophony, the stereo dipole, and the optimal source distribution have been tested on the optimal listening positions, following a discussion on the template matching process of the model. The simulation results suggest that the current model, with certain limitations, can be a good predictor of the fidelity of such systems in providing a virtual sound image.
Convention Paper 6854 (Purchase now)

P29-10 Evaluation of Packet Loss Distortion in Audio SignalsJan Erik Voldhaug, Erik Hellerud, U. Peter Svensson, Norwegian University of Science and Technology - Trondheim Norway
Audio streamed over best effort packet switched networks under real-time requirements may be distorted by lost or delayed packets. In this work triple stimulus hidden reference subjective tests are used to evaluate the perceptual quality of audio signals exposed to packet loss. The effects of packet loss combined with both very simple and very complex error concealment schemes are evaluated, together with four different packet loss rates and five audio clips. Results show statistically significant differences between different packet loss rates, error concealment schemes, and audio clips. Results are also compared with output from an objective audio quality evaluation tool (PEAQ).
Convention Paper 6855 (Purchase now)

P29-11 Dithering Strategy Applied to Tinnitus MaskingAndrzej Czyzewski, Gdansk University of Technology - Gdansk, Poland; Bozena Kostek, Gdansk University of Technology - Gdansk, Poland, International Center of Hearing and Speech, Warsaw, Poland; Krzysztof Kochanek, Henryk Skarzynski, International Center of Hearing and Speech - Warsaw, Poland
The hypothesis on the existence of a parasitic quantization that accompanies hearing loss has been formulated in this paper and then related to other existing theories on causes of tinnitus. Some preliminary experiments have been carried out to verify the correctness of the proposed interpretation of applied maskers employing dither theory. An effective method of providing a masking signal that uses bone conductivity was derived for the purpose of these experiments. The results of the experiments initially confirm the analogy between the threshold phenomena occurring in the digital audio circuits and ear noises origin. The presented results may induce the elaboration of more effective ear therapies based on high-frequency dither having specially formed spectral characteristics.
Convention Paper 6856 (Purchase now)

  (C) 2006, Audio Engineering Society, Inc.