Impression Of Room Research Articles

Towards a better understanding of multimodal integration and sensorimotor adaptation to audiovisual environmental incongruence using Virtual Reality

People use previous knowledge and in situ judgment to produce speech with a vocal effort appropriate to a given environment’s acoustics. To test how people integrate auditory and visual cues in speech production, we employed a three-by-three cross-conditional audiovisual match-mismatch paradigm. Three visually distinct environments with three different room acoustics were selected: a gymnasium, a classroom, and a hemi-anechoic room. The visual environment was presented with a Virtual Reality (VR) headset and the auditory environment was a diffuse room impression, playing back the participants’ speech through loudspeakers in the room with different reverberation times. Participants were prompted to speak in all nine combinations of the audiovisual conditions, with three being congruent and six incongruent. Linear mixed-effects regression modeling was used to evaluate the effect of the audiovisual manipulations and time course on mean intensity. Preliminary results indicate that participants initially spoke at a level that matched the visual expectation and then adapted to the audio condition; detailed analysis of the time course of adaptation is ongoing and will be presented. This study furthers our understanding of multimodal integration and the sensorimotor adaptation of speech production, which finds applications in fields including communication in noise and VR soundscape design.

Synthesis of acoustics of coupled volumes—Perceptual approach

Connected, acoustically coupled spaces are typically characterized by non-exponential decay with double or multiple slopes. In some cases, two volumes of different absorption characteristics are connected through an aperture that may be opened to vary the engagement between the two acoustics, e.g., the auditorium and the reverb chamber. In a large complex room, acoustic energy emanating from the source will simultaneously and sequentially engage a number of different volumes (regions), depending on how the space is physically laid out, and where the source and receiver are. The regions shape and exchange energy collectively. The listener’s overall room impression will be due to an overlayed mix of spatially and temporally distributed ambient responses reaching the listener or receiver position. In synthesis of complex acoustic spaces, we take a perceptual approach where we combine elements of measured spatial room impulse responses, divide them into meaningful temporal segments, shape their envelopes, and recombine these varied characteristics for multichannel convolution with a source. Different variants of processing the impulse responses create different perceptual outcomes, and a variety of aurally diverse spaces can be created for applications in virtual acoustics and immersive audio production. These perceptual approaches, balancing clarity and reverberation, will be discussed in this presentation.

The percept of reverberation is not affected by visual room impression in virtual environments.

Humans possess mechanisms to suppress distracting early sound reflections, summarized as the precedence effect. Recent work shows that precedence is affected by visual stimulation. This paper investigates possible effects of visual stimulation on the perception of later reflections, i.e., reverberation. In a highly immersive audio-visual virtual reality environment, subjects were asked to quantify reverberation in conditions where simultaneously presented auditory and visual stimuli either match in room identity, sound source azimuth, and sound source distance, or diverge in one of these aspects. While subjects reliably judged reverberation across acoustic environments, the visual room impression did not affect reverberation estimates.

Investigation of listener envelopment using spherical microphone array measurements and ambisonics playback

An important aspect of overall room impression is listener envelopment (LEV), the sense of being immersed in a sound field. Current LEV objective metrics are primarily based on lateral reflections, typically measured with a figure-of-eight microphone. The purpose of this study was to investigate LEV using measured impulse responses (IRs) taken with an Eigenmike 32-element spherical microphone array as an initial step toward creating a new metric for LEV. The spherical array enables a spatial analysis with higher resolution than traditional methods. Impulse response measurements were made in the Peter Kiewit Concert Hall in Omaha, NE, in several seat positions and hall absorption settings. Auralizations were generated by convolving the measured IRs with anechoic music excerpts and then processing the signals for third-order ambisonics playback. The signals were played over an array consisting of 32 loudspeakers in an anechoic chamber. A subjective study was run in which musically trained listeners rated the LEV of the stimuli. Beamforming techniques were used to analyze the IRs to better understand the spatial and temporal factors that contribute to the perception of envelopment. Results will be presented, which correlate the objective measurements to the subjective ratings. [Work supported by NSF Grant 1302741.]

Connecting the sense of envelopment to specific components of the sound field using perceptually motivated auralizations

Envelopment is known to be a key attribute related to overall room impression. Despite this importance, limited research has been done to identify the specific components of the sound field that contribute to envelopment. The goal of this study was to determine the timing and spatial distribution of reflections contributing to envelopment. A subjective study was conducted using a range of simulated auralizations, which were played back over a three-dimensional loudspeaker array in an anechoic chamber. For each auralization, subjects rated their perceived envelopment. A real-time acoustic simulation program was developed in Max to generate the signals, which simulated early sound with the image-source method and late sound with statistical reverberation. When creating the stimuli, the program produced immediate auditory feedback in response to adjusting the input parameters. The signals were quantified through impulse response measurements to ensure a wide range of conditions. The subjects’ envelopment ratings were correlated to different components of the sound field, to evaluate how specific arrival time of reflections and spatial characteristics contribute to envelopment. These results could possibly be used to determine the effectiveness of existing envelopment metrics and potentially contribute to developing a new measure to predict envelopment. [Work supported by NSF Award-1302741.]

Duration Required for Steady State Color Adaptation at the Change between Chromatic and White Lights

New illuminants, such as LEDs or OELs that can vary their own color, are expected to spread. The opportunities when colored lights are used in lighting are currently increasing. Research on the impression of rooms by the colored light used in the lighting is important knowledge about the adaptation transition at the change of the lighting between chromatic colors. This paper reports the results about the duration necessary for steady adaptation based on the color appearance of the light when the light color changes between chromatic and white. The duration of the necessary adaptation to white light from some chromatic light is shorter than that to chromatic light from white light. The duration of adaptation to chromatic light from white light and that to white light from chromatic light becomes longer with vivid chromatic light.

Width or Height? Which has the Strongest Impact on the Size Impression of Rooms? Results from Full-Scale Studies and Computer Simulations

Full-scale studies of small rooms were conducted to find out whether width or height has a stronger influence on the size impression of the room. The study also investigated whether this question can be answered using computer simulation. Two simulation programs were used in the study: ArchiCAD and Radiance, the most advanced lighting simulation program. The results from full-scale studies carried out with school children indicate that width has a stronger positive impact on size impression than height. The difference is much more evident in richly daylit rooms than in gloomy ones. However, a similar full-scale study carried with architectural students did not support this finding. It is not clear if the difference between school children and architecture students is caused by the eye height of the observers, the unique experience with architectural space that architect students have, or both. Computer simulation studies showed that the size impression of the appearance of a room by looking at virtually generated pictures might be different from the size impression of the room built in full-scale. The main question addressed by the paper—width or height—cannot be answered with the aid of computer simulations alone.

Sound-focusing effects in the plan of horse-shoe shaped opera theatres

An acoustical feature reported specifically for Italian-style opera houses is the non uniformity of early sound in the stalls. The curvature of the lower part of the lateral walls produces a sort of partial wave-guiding effect, like the well known "whispering gallery" effect, that is responsible of the concentration of early sound energy at seats located back in the stalls when the sound source radiates from the foreground of the stage floor. As much of the global room impression depends on the early part of the impulse response it can be supposed that the perceived sound quality of singers' voice and instrumentalists' music performing on the stage will be much different if the listener seats in the last rows with respect to different locations in the stalls. This paper reports an objective analysis on this subject based on measurements carried out in the stalls of a baroque-type theatre. Relevant computer simulations were also implemented.

Change in the impression of rooms with interior wood finishes arranged differently: questionnaire survey with the use of photographs for the analysis of impressions of rooms concerning living activities

Efforts were made to quantify the impact of visual stimulation from interior wood finishes on the impression of room interiors, using feelings about living activities as indicators. Four types of room interiors with interior wood finishes used in different proportions were simulated. The room interiors were photographed from the same viewpoint. A survey was conducted by interviewing 200 test subjects. As a result of the analysis of principal components, it was found that desires of living activities obtained from the four photographs consisted of two factors: desires for calmness and desires for activities. A great desire for calmness was obtained from photographs showing wood materials. A weak desire for calmness and a strong desire for activities were obtained from a photograph that showed no wood materials. Great desires for both calmness and activities were obtained from a photograph showing wood materials used only as flooring material. As for an evaluation of “living,” the photograph of a room interior without wooden materials was evaluated as a place that test subjects did not feel like living in. The photograph showing wood materials used only as flooring material was evaluated as the place that test subjects most felt like living in, and considered most suitable as a living space.

The Impact of Window Form on the Size Impression of the Room—Full-Scale Studies

Full-scale studies of a small room were carried out at Norwegian University of Science and Technology, Norway, to find out in which way the form of window(s) influence the size impression of a little room. Care was also taken to find out if the impression is due to the form of the window alone, daylight falling through it, or to both. The results indicate that the impression of room dimensions depends on window form, even if the total glazing area is equal. Generally, vertical windows make that the room appear higher, horizontal make it wider. The visual impression of the room depends also to a high degree on the placing of the window in relation to the neighboring surfaces: sidewalls, floor and ceiling. The window adjacent to a sidewall contributes to higher luminance of this wall, it appears as being further away from the observer; the room appears as wider. The same principle is true for windows adjacent to the ceiling or floor. They contribute to increasing the impression of height. The study was carried in rooms having high reflectances on all surfaces, the enlarging effect of the window adjacent to the neighboring surface may not be that clear in rooms having dark surfaces.

The Impression of Room Given by Communication Window Lighting

The Impression of Room Given by Communication Window Lighting

Late lateral energy fractions and the envelopment question in concert halls

In concert hall acoustics, spatial perception is a crucial element of the experience, yet several questions remain unresolved. In the 1960s, there was some work on what was then called ‘room impression’ caused by diffuse reverberation. The possible importance of early lateral reflections was proposed in 1967 by Marshall [Marshall AH. A note on the importance of room cross-section in concert halls. Journal of Sound and Vibration 1967;5:100–12] and until recently concern for the effect of early reflections has overshadowed study of the spatial effects linked to the later sound. Bradley and Soulodre [Bradley JS, Soulodre GA. The influence of late arriving energy on spatial impression. Journal of the Acoustical Society of America 1995;97:2263–71; Bradley JS, Soulodre GA. Objective measures of listener envelopment. Journal of the Acoustical Society of America 1995;98;2590–7] have now suggested that early reflections are predominantly responsible for creating a sense of source broadening [and apparent source width (ASW)], whereas a sense of envelopment, which had on occasions been linked to ASW, is almost solely produced by later lateral reflections. Bradley and Soulodre have proposed the late lateral energy level as a measure of listener envelopment (LEV). This paper considers some of the history of spatial perception in concert halls and reports on measured results made in 17 halls of the late lateral energy fraction (LLF) and the late lateral energy level (GLL). The spread of measured values of LLF turned out to be small and GLL was found to be predominantly determined by the total acoustic absorption of halls.

Neisseria mucosa septicemia

A 71-yr-old male presented in the emergency room with a history of several days of fever, chills, nonproductive cough, weakness, anorexia, and generalized malaise. Significantly, his history included mitral and aortic valve replacement a year earlier. On physical examination, the patient's heart showed an irregular rhythm and the electrocardiogram suggested atrial fibrillation with rapid ventricular response. His white blood cell count was elevated at 17,600/mm 3 (normal 4,800 to 10,800); his platelet count was depleted at 36,000/mm 3 (normal 130,000 to 400,000). The initial emergency room impression was that of atrial fibrillation, thrombocytopenia, and leukocytosis. The patient was admitted for further evaluation for chronic congestive heart failure, with hypertension and possible upper respiratory infection. Suggested differential diagnoses included urinary tract infection, endocarditis, cholecystitis or ascending cholangitis, and/or sepsis of unknown origin. An echocardiogram did not suggest any superimposed vege-

Definition eines raumeindrucksmasses [formula omitted] zur bestimmung des raumeindrucks bei musikdarbietungen auf der grundlage subjektiver untersuchungen

The subjective impression of a room is an essential characteristic of the judgement of the acoustics of a concert hall. In parallel, the investigation ‘Synthetic Sound Fields’ will define a room impression index R which can be derived from the impulse response of the room. The correlation between the calculated room impression index R and the subjective judgement of room impression for 125 test sound fields was highly significant. A significant correlation is also obtained between the subjective impression in concert halls and the measured values of room impression index R.