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AES Amsterdam 2008
Psychoacoustics, Perception, and Listening Tests - 2
Paper Session P23
Tuesday, May 20, 09:30 — 12:00
Chair: Joerg Bitzer, University of Applied Science Oldenburg - Oldenburg, Germany
P23-1 A Proposed Audio Visual Product Measure—Joe Peters, National University of Singapore - Singapore
The Multimedia Section at the Centre for Instructional Technology at the National University of Singapore has developed an audio visual assessment index (AVAI) to serve as a tool for clients to measure their evaluation of audio and video products. AVAI is based on a listing of indicators and variables that make up the fundamental elements in the capture and processing of AV products (video production): image, color, light, audio, form, aesthetics, and delivery. AVAI is currently being used by professionals for internal evaluation. A series of simulator-based AVAI courses are also underway, the purpose of which is to enable lay persons to understand the indicators and variables through simulated explanations. The thesis is, that in order to keep product value high the information gap between the producers and the lay clients must be narrowed. The sub-set of this thesis is that this narrowing can be achieved through even a singular simulator training session. What is presented in this paper is the conceptual framework and some preliminary tests. The tests are not substantial as studies are slow. AVAI is not a core area of the work of the Multimedia Section handling this study. Nevertheless, it is important to have some response from AES on this preliminary presentation.
Convention Paper 7460 (Purchase now)
P23-2 Nonexistence of Frontal Signal Unmasking from Spatially Wide Masker—Ville Pulkki, Jukka Ahonen, Helsinki University of Technology - Espoo, Finland
The masking of a frontal signal by spatially wide noise sources was investigated in a listening experiment. The noise sources consisted of a single or multiple symmetrically positioned loudspeakers in the frontal horizontal plane in anechoic conditions. It is shown that the detection threshold of the signal does not depend on masker width, which suggests that frontal unmasking does not exist in loudspeaker listening. In additional tests with signal source positioned in side it is shown that moderately small binaural unmasking occurs in that case from wide masker, and that increasing the width of masker source decreases binaural unmasking effect.
Convention Paper 7461 (Purchase now)
P23-3 Reaction Times and Performances in Recognition Tasks to Assess Speech Quality—Virginie Durin, Laetitia Gros, Orange Labs - Lannion, France; Gilles Hericher, Laboraoire Psychologie et Neurosciences de la cognition - Mont Saint Aignan, France
This paper deals with perceptive test methodologies to assess speech quality of telecommunication systems. Faced with drawbacks of typical methodologies ecommended by ITU-T, a new way to assess speech quality is investigated, by collecting reaction times and performances when subjects are achieving tasks involving degraded speech signals. A duel task with a digit recognition memory task and a letter recognition task is proposed. Three different quality levels are applied to audio signals describing digits and letters. The
results show significant differences of performances and reaction times between the three quality levels.
Convention Paper 7490 (Purchase now)
P23-4 Evaluation of Stereophonic Images with Listening Tests and Model Simulations—Munhum Park, Philip Nelson, University of Southampton - Highfield, Southampton, UK; Kyeong Ok Kang, Electronics and Telecommunications Research Institute (ETRI) - Daejeon, Korea
A binaural hearing model has recently been suggested for the evaluation of the performance of virtual acoustic imaging systems. The model considers excitation-inhibition (EI) cell activity patterns as the internal representation of sound localization cues and a pattern-matching procedure with a frequency-weighting scheme produces the estimate of source location in the horizontal plane. Given the reasonable prediction of some important features in human sound localization and lateralization, this paper presents a further verification and application of the model in actual listening tests. In this paper participants' responses to stereophonic images have been compared with the predictions of the model, individually established from the subject's own HRTF. Model predictions have been found to be both qualitatively and quantitatively consistent with the test results, and in particular, the agreement between 2 and 3 kHz gave a good indication that, unlike some similar models, the current model can effectively incorporate both ITD and ILD information according to their relative importance.
Convention Paper 7463 (Purchase now)
P23-5 The Sound Character Space of Spectrally Distorted Telephone Speech and its Impact on Quality—Marcel Wältermann, Alexander Raake, Sebastian Möller, Berlin University of Technology - Berlin, Germany
Spectral distortions of speech transmitted over a telephone channel may stem from linear channel filtering, codecs, electro-acoustic properties of end-user terminals, or the acoustic environment at send side. In this paper a study is presented that aims at revealing the perceptual space of spectrally distorted telephone speech and establishing a link to the overall quality of the speech. Two dimensions were identified as relevant for explaining the perceived quality: indirectness and brightness. Whereas brightness is related to the center frequency of a transfer function, indirectness is correlated with the equivalent rectangular bandwidth and constitutes the dominating factor in the perceptual space in terms of covered variance. The concept of the bandwidth impairment factor that fits into the framework of the so-called E-Model and that is based on these simple parameters for computing the integral quality of spectrally distorted speech could successfully be applied to the given data.
Convention Paper 7464 (Purchase now)
Last Updated: 20080612, tendeloo