This article presents a user experiment that assesses the feeling of spatial presence, defined as the sense of “being there” in both a real and a remote environment (respectively the so-called “natural presence” and “telepresence”). Twenty-eight participants performed a 3D-pointing task while being either physically located in a real office or remotely transported by a teleoperation system. The evaluation also included the effect of combining audio and visual rendering. Spatial presence and its components were evaluated using the ITC-SOPI questionnaire (Lessiter, Freeman, Keogh, & Davidoff, 2001 ). In addition, objective metrics based on user performance and behavioral indicators were logged. Results indicate that participants experienced a higher sense of spatial presence in the remote environment (hyper-presence), and a higher ecological validity. In contrast, objective metrics prove higher in the real environment, which highlights the absence of correlation between spatial presence and the objective metrics used in the experiment. Moreover, results show the benefit of adding audio rendering in both environments to increase the sense of spatial presence, the performance of participants, and their engagement during the task.

While auralization technology is used in a variety of fields, particularly in architectural acoustics, there is a lack of data on the auralization tools used and actual practices. In this perspective, this work presents the results of a survey study on auralization uses in the acoustical design and consulting community, targeting acoustical consultants. The objectives are (1) to identify the tools and methods used by acousticians to create auralizations as well as effective uses so as to understand the benefits and changes provided by this technology, and (2) to highlight the difficulties and limitations linked to the use of auralizations in concrete projects. Based on the theory of acceptability and use of technology, the study was conducted from a mix of quantitative and qualitative data collection approaches, combining a questionnaire answered by 74 respondents with semi-directed interviews with nine practitioners. Results highlight the main uses of auralizations, the diversity of projects in which auralizations are applied, and how auralizations are currently used in real-world situations. The benefits of using this technology, inherent weaknesses in the tools, and practical difficulties are also discussed.

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The speech intelligibility index (SII) calculation is based on the assumption that the effective range of signal-to-noise ratio (SNR) regarding speech intelligibility is [− 15 dB; +15 dB]. In a specific frequency band, speech intelligibility would remain constant by varying the SNRs above + 15 dB or below − 15 dB. These assumptions were tested in four experiments measuring speech reception thresholds (SRTs) with a speech target and speech-spectrum noise, while attenuating target or noise above or below 1400 Hz, with different levels of attenuation in order to test different SNRs in the two bands. SRT varied linearly with attenuation at low-attenuation levels and an asymptote was reached for high-attenuation levels. However, this asymptote was reached (intelligibility was not influenced by further attenuation) for different attenuation levels across experiments. The − 15-dB SII limit was confirmed for highpass filtered targets, whereas for low-pass filtered targets, intelligibility was further impaired by decreasing the SNR below − 15 dB (until − 37 dB) in the high-frequency band. For high-pass and low-pass filtered noises, speech intelligibility kept improving when increasing the SNR in the rejected band beyond + 15 dB (up to 43 dB). Before reaching the asymptote, a 10-dB increase of SNR obtained by filtering the noise resulted in a larger decrease of SRT than a corresponding 10-dB decrease of SNR obtained by filtering the target (the slopes SRT/attenuation were different depending on which source was filtered). These results question the use of the SNR range and the importance function adopted by the SII when considering sharply filtered signals.Keywords Speech intelligibility index · Speech in noise · Speech intelligibility measurement 258 T. Leclère et al.

This paper presents an experiment assessing the feeling of spatial presence in both real and remote environments (respectively the socalled "natural presence" and "telepresence"). Twenty-eight (28) participants performed a 3D-pointing task while being located in a real office and the same office remotely rendered over HMD. The spatial presence was evaluated by means of the ITC-SOPI questionnaire and users' behaviour analysis (trajectories of head during the task). The analysis also included the effect of different levels of immersion of the system-visual-only versus visual and audio-rendering in such environments. The results show a higher sense of spatial presence for the remote condition, regardless of the degree of immersion, and for the "visual and audio" condition regardless of the environment. Additionally, trajectory analysis of users' heads reveals that participants behaved similarly in both environments.

Auralization technology has reached a satisfactory level of ecological validity, enabling its use in architectural acoustic design. Only recently have the actual uses of auralization in the consulting community been explored, resulting in the identification of a variety of uses, including (1) to present to clients, (2) to test design ideas, (3) as a verification tool, (4) as a verification tool, (5) as a marketing tool, and (6) to improve internal company discussions. Taking advantage of methodologies from ergonomics research, the present study investigates effective uses through the observation of a collaboration project between an acoustic research team and an acoustic consultant, as a case study. Two spaces have been auralized in the context of the conception of a new skyscraper during the design phase of the project. The two spaces faced different problematics: an Atrium for which three different acoustic treatment options were suggested and experienced through multi-modal auralizations and audio-only auralizations of an Auditorium where an intrusive noise was to be acoustically treated. The ergonomic observation and analysis of this project revealed key impediments to the integration of auralization in common acoustic design practices.

Auralization renderings have reached a sufficient level of maturity that simulated auralizations can be comparable to measured ones. These auralizations can be rendered over a variety of sound systems, potentially combined with a visual model through VR interfaces. This study presents a perceptual evaluation of auralizations of a small ensemble virtual concert rendering, comparing a tracked binaural rendering to 2nd order Ambisonic rendering over a 32 loudspeaker array. The geometrical acoustic model of several actual performance spaces were created and then calibrated using in situ omni-directional room impulse response measurements. The performance stimuli consisted of 3 extracts of jazz anechoic recordings comprising trios and quartet ensembles, augmented by three-dimensional visual point-clouds of the musicians playing on stage. Participants of the listening test included a range of listening expertise level (acousticians, architects, students). Several room acoustical parameters were evaluated between rendering systems, seating positions, and rooms.

Auralizations can be computed in a variety of ways as well as be rendered over different sound reproduction systems. They are used as a design tool in architectural projects and for fundamental studies on spatial perception and cognition, hence requiring reliability and confidence in the obtained results. This study assessed this reliability through auditory perception stability by comparing the perceived differences between two rendering systems for a given set of second-order Ambisonic auralizations: virtual loudspeaker binaural rendering over head-tracked headphones versus 32-loudspeaker rendering. Anechoic extracts of jazz pieces have been recorded and presented in various acoustic conditions over these two systems, evaluated on the following criteria: Readability, distance, listener envelopment (LEV), apparent source width (ASW), reverberance, and loudness. Results show that consistent significant differences between scene conditions are comparably perceived across the two systems. However, significant effects of the sound reproduction system were observed for ASW, LEV, and reverberance in some configurations. V