1,720,989 research outputs found
From Tangible to Intangible Heritage inside Italian Historical Opera Houses
No full textHistorical opera houses in Italy have been the place for the development of a relevant part of the National musical tradition and their design is paired with a peculiar acoustical fingerprint. Due to its relevance this can be regarded as an intangible heritage embedded in the tangible heritage constituted by the theatre building itself. In particular the presence of fairly deep lateral enclosures opened to the main hall volume, called the “boxes,” is of paramount importance for the implications it had on the listening experience perceived by the public. For instance, the positions in the box recess had a much less favourable sound field compared to the frontal ones located at the box opening towards the hall. In this work the need for the box design is briefly recalled from an historical perspective and then the sound field in the boxes is described as the combination of several sound reflections from specific interior surfaces. It is seen how the related listening experience can vary in a remarkable manner while moving from boxes at different tiers. This characteristic greatly differentiates historical opera houses from modern ones, where one of the most valuable attribute is a limited change in acoustics over large audiences. The acoustical environment of historical halls and inside boxes in particular was important in building up the ear of the Italian opera goers, thus a close consideration of the peculiarities of the intangible heritage is necessary in case of restorations and cannot be overlooked
How Reliable are 11- to 13-Year-Olds’ Self-Ratings of Effort in Noisy Conditions?
No full textPerforming a task in noisy conditions is effortful. This is especially relevant for children in classrooms as the effort involved could impair their learning and academic achievements. Numerous studies have investigated how to use behavioral and physiological methods to measure effort, but limited data are available on how well school-aged children rate effort in their classrooms. This study examines whether and how self-ratings can be used to describe the effort children perceive while working in a noisy classroom. This is done by assessing the effect of listening condition on self-rated effort in a group of 182 children 11–13 years old. The children performed three tasks typical of daily classroom activities (speech perception, sentence comprehension, and mental calculation) in three listening conditions (quiet, traffic noise, and classroom noise). After completing each task, they rated their perceived task-related effort on a five-point scale. Their task accuracy and response times (RTs) were recorded (the latter as a behavioral measure of task-related effort). Participants scored higher (more effort) on their self-ratings in the noisy conditions than in quiet. Their self-ratings were also sensitive to the type of background noise, but only for the speech perception task, suggesting that children might not be fully aware of the disruptive effect of background noise. A repeated-measures correlation analysis was run to explore the possible relationship between the three study outcomes (accuracy, self-ratings, and RTs). Self-ratings correlated with accuracy (in all tasks) and with RTs (only in the speech perception task), suggesting that the relationship between different measures of listening effort might depend on the task. Overall, the present findings indicate that self-reports could be useful for measuring changes in school-aged children’s perceived listening effort. More research is needed to better understand, and consequently manage, the individual factors that might affect children’s self-ratings (e.g., motivation) and to devise an appropriate response format
Le proprietà statistiche del cammino libero medio come strumento d’indagine delle proprietà acustiche delle sale teatrali
No full textCalculating the speech transmission index in fluctuating noise: A data-driven approach in the short-term implementation
No full textEveryday communication takes place in the concurrent presence of reverberation and background noise; the latter may have a fluctuating character and a speech-like spectrum, being for instance the result of multiple speakers talking together in the background (i.e., babble noise). The objective characterization of these listening conditions can be achieved by using a time-frame implementation of the Speech Transmission Index (STI) in the indirect scheme, named eSTI. One prerequisite of using the method is that the optimal time frame has to be determined. In this study, an experimental approach was used to determine the optimal time frame, defined as the one that provides coincident psychometric curves under stationary and fluctuating background noises. Matrixed-word listening tests were presented to 79 young adults with normal hearing. The speech reception task was presented under 26 listening conditions, created by varying signal-to-noise ratio, reverberation and noise type. By comparing the psychometric curves for the two noises, an interval of suitable frame durations was identified, ranging between 200 and 345 ms. Using a time frame within this interval thus ensures that the same eSTI value corresponds to the same predicted intelligibility, irrespective of the noise type
An experimental study of a time-frame implementation of the Speech Transmission Index in fluctuating speech-like noise conditions
No full textEveryday communication takes place in the combined presence of reverberation and background noise, the latter having in some cases fluctuating characteristics and speech-like spectrum. To predict the speech intelligibility for fluctuating maskers, a time-frame implementation of the Speech Transmission Index (STI) in the indirect measurement scheme, named Extended STI (eSTI), has been recently proposed. Stationary speech spectrum noise is used as the probe signal and the a priori knowledge of the impulse response characterizing the transmission chain is required. A key issue of eSTI is the selection of the appropriate time frame for the calculations, whose duration is here assessed by a systematic experimental approach. Listening tests are developed for the scope, using speech-like stationary and fluctuating noises as maskers and rendering sound fields with various reverberation times and over a wide range of signal-to-noise ratios. An interval of frame durations providing equivalent values of eSTI under the two noises is identified. Within the target interval, statistically coincident psychometric curves are obtained for the two noises, thus ensuring that the same eSTI corresponds to the same speech intelligibility
Effects of multiple early diffuse reflections on spatial percepts
No full textWhile the use of diffuse surfaces is becoming increasingly common in the acoustical design of performance venues and normal rooms, there is a paucity of data on the auditory perceptual effects that characterize those finishes compared to specular ones. For instance, it is not entirely clear whether and how the aural impression is affected when first reflections are swapped from specular to diffuse. In a recent work, after revising the background knowledge on physical and perceptual effects of scattering, Visentin et al. [(2020) J. Acoust. Soc. Am. 148(1), 122-140] started a systematic analysis of how diffuse reflections influence the auditory impression by considering the simplest possible case, that is, a direct sound and one lateral reflection. The present work is a step forward in the analysis, and pairs of lateral reflections without or with a ceiling reflection are considered. By means of detailed listening tests, it is shown how diffuse reflections modulate the perception of some spatial attributes. This knowledge adds to the criteria to be employed when including diffusing surfaces in the design of first reflections in rooms
Effect of a single lateral diffuse reflection on spatial percepts and speech intelligibility
No full textThis study examines the influence of an early lateral reflection on spatial perceptual attributes and speech reception. To this aim, a diffuse reflection is compared with a specular one. Although diffusive surfaces have widespread applications in room acoustics design, the knowledge of the perceptual and behavioral outcomes of these surfaces has yet to be fully developed. Two experiments were conducted to investigate how the reflection type, its temporal delay, and its azimuth affect spatial percepts (source distance, width, and focus) and speech intelligibility (SI) in diffuse stationary noise. The experimental setup included ecological elements: field measurements, a speaker-like source directivity, and real flat and diffusive surfaces. The results indicate that the presence of a single diffuse reflection reduces the perceived distance of a frontal speech source and makes it clearer. SI is higher with a diffuse reflection than with a specular one. Perceptual and behavioral outcomes both depend on the angle of reflection given the frequency- and angular-dependent properties of the diffusing surface and the directivity of the speech source. The results are interpreted with reference to loudness and binaural cues and to the precedence effect. Implications of the findings for acoustic design are also discussed
Comparing the effects of scattered and specular sound reflections on speech intelligibility in rooms
No full textSpeech intelligibility in rooms is assumed to depend on the amount of reverberation, and on the distribution of
sound energy in the impulse response between early and later reflections, the former being considered beneficial,
the latter detrimental. This assumption is based on the analysis of a single channel, which is monaural. When the
binaural capacities of the auditory system are considered, other phenomena come into play, supporting speech
recognition mainly by comparing signal levels and times of arrival at the ears. Starting from these basic
mechanisms, the present work shows that, for given monaural conditions, binaural cues are influenced by the
type of sound reflections in a room via the correlations they produce on the signals at the ears. A fully scattering
scenario, and a totally flat boundary scenario were used to investigate listeners’ performance in a speech
intelligibility task in a virtual room with spatialized noise conditions. The amount of correlation at the ears of the
listener of the signals coming from both the source and the masker were found to affect speech intelligibility - the
stronger either correlation, the greater the speech intelligibility - and their joint effect was larger than the two
effects taken separately. A specular setting for the sound reflections was associated with both better reception
thresholds and a better usage of spatial cues when deciphering speech. The implications for the acoustic design of
rooms with a view to facilitating speech intelligibility are discussed
Out of the noise: Effects of sound environment on maths performance in middle-school students
No full textThe main goal of the present research is to gain a better understanding of the consequences of background noise on learning, with a specific focus on how noise may impair maths achievement. A mental calculation task was administered in the classroom to 162 middle-school students (11–13 years old). The listening conditions were manipulated, choosing three different conditions - quiet, traffic and classroom noise - to reflect realistic noise exposure experienced in urban classrooms. A differential negative effect of listening condition on maths performance emerged in relation to task difficulty and children's age. The youngest children performed better in the quiet and traffic noise conditions than in the classroom noise condition, while in the older children these differences gradually disappeared. The detrimental effect of classroom noise was most evident when the maths task was moderately difficult. With increasing task complexity, the difference between listening conditions faded. These data support the idea that younger children are more susceptible to the detrimental effects of noise in school classrooms than older children, and that their academic attainments are affected. Our findings have implications for classroom learning because different types of environmental noise affected children's performance differently, depending on the complexity of the task in hand
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