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This paper presents the results of an extended experiment to assess the impact of individualized binaural rendering on player performance in an ecologically valid use context, specifically that of a VR “shooter game,” as part of a larger project to characterize the impact of binaural rendering quality in various VR type applications. Participants played a simple game in which they were faced with successive targets approaching from random directions on a sphere. While audio-visual cues allowed for general target localization, only sections of the game that relied on audio cues were used for analysis. Two HRTF exposure protocols were used, comprising best and worst-match HRTFs from a “perceptually orthogonal” optimized set of HRTFs, during the course of six game sessions. Two groups performed the game sessions exclusively using either their best or worst-match HRTF. Two additional groups performed the game sessions alternating between best and worst-match HRTFs. Results suggest that HRTF quality had minimal general impact on in-game participant performance and improvement rate. However, performance for extreme elevation target positions was affected by the quality of HRTF matching. In addition, a subgroup of participants showed higher sensitivity to HRTF choice than others.
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We investigate a procedural model for synthesizing applause sounds that contains novel aspects to ensure high quality and usability. Synthesis of a single clap is generated as a result of filtering a noise source and applying an envelope with exponential decay, based on prior art and existing experimental data. An ensemble approach is introduced to simulate many clappers in a spatially distributed environment. This renders how applause interacts with the space in which it is hosted, including the room impulse response, and where each clap is situated relative to the listener’s position. The applause features realistic build-up and fadeout based on natural audience response. The implementation contains meaningful parameters that allow a user to configure and change the sound to achieve a multitude of different types of applause, such as an “enthusiasm parameter” to simulate the greater perceived intensity from an enthusiastic audience. Subjective evaluation was performed to compare our method against recorded samples and four other popular sound synthesis techniques. It showed that the pro- posed implementation produced significantly more realistic results than other forms of applause synthesis, and it was almost indistinguishable from real-life recordings.
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The recent resurgence of vinyl music records sales led by a consumer demand is increasing faster than production capability. This has resulted in supply delays across the sector. Thus far, manufacturing investments have been focused on traditional proven methods rather than alternative technologies. This paper demonstrates for the first time the production of a stereo recording via analog methodology using a single pulsed laser beam. Using mid-side theory, to combine a sum (mono) signal with a difference signal, a 532nm Nd:Yag laser beam was used to process high-impact polystyrene discs (HIPS). Stereo recordings were manufactured by varying the laser power to produce a difference signal and deflecting the beam with a mirror mounted galvanometer to produce the sum signal. Upon playback on a conventional turntable, the recordings were analyzed with an oscilloscope and stereo separation was observed. To our knowledge this is the first time a stereo signal has been successfully recorded using a single laser beam. Previous literature has used a single laser beam to achieve mono signals and required significant digital pre-processing of the audio source. This new methodology requires lower investment costs than traditional pressing plants and would make volume-tailored production more affordable.
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This article deals with subjective tests of speech intelligibility. A set of samples in the Czech language, recorded by four dif- ferent narrators, was distorted with different noise levels and encoded by a low bit-rate encoder. The subjective test consisted of two parts. The first part (45 participants) proceeded according to the ITU-T Recommendation P.807 - Subjective test methodology for assessing speech intelligibility. The second part (70 participants) included an additional (parallel) psycho- motor task deploying a laser-shooting simulator, in which subjects had the roles of shooters and counters. The purpose of the parallel task is to bring the testing closer to the real use of technology. Significant differences have been found in the results of the intelligibility of samples from different speakers. There were also differences in evaluation with and without a parallel task. Samples from male narrators have a significantly higher intelligibility score in the standard laboratory test but also show a greater decrease in intelligibility after engaging a parallel task.
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The issues of reverberation in acoustic architecture and music production share the same theoretical core; nevertheless the first one has been scientifically researched in depth while the second one remains at technical and experimental crossroads. It could be stated that the ISO 3382 parameters were proposed in the “analog” era for room acoustics (actual halls) whereasthe “digital” parameters introduced in software, artificial reverbs, are not standardized in any way but help to create desired reverberation for music or audio effects. The interest herein is to bind these two disciplines together and analyze some of the significant descriptors of room acoustics (RT, C50, C80, BR, ER, CT) applied in plug-in reverberant processors to observe how the virtual space is affected by changing the values of different parameters. Psychoacoustic ranges of JND were applied to conclude their relevance (or rather influence) and whether it is possible to perceive alteration. Five of the selected popular and commercial VST reverbs are juxtaposed with five similar settings and the results of analysis might be useful for sound mixers and automated mixing algorithms.
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With care and good advance planning it is possible to preserve and document current digital projects, and to reconstruct old ones. Multitrack tape projects are particularly challenging for the archivist. While old analog formats can be dealt with after many years, the first two decades of digital recordings need rapid attention while there are still machines around that work or can be fixed.
