Poor Acoustic Quality Research Articles

On the effect of indoor acoustic conditions in performing cognitive tests in primary school

The quality of the acoustic environment is essential to foster learning as students learn by listening to the teacher. Prolonged exposure to noise during critical learning periods at school can impair development and have a lifelong effect on academic achievement. This is why the problem of noise is of concern in learning environments such as schools. Poor acoustic quality leads to increased cognitive effort that is associated with greater difficulty in processing and remembering information in the short and long term. Preliminary results from the administration of neuropsychological tests under quiet and noise conditions only partially supported the hypothesis that noise negatively impacts children's cognitive performance. In fact, only in one of the two monitored schools the children's performance was affected by the presence of noise during the execution of the tests. In this paper, new results obtained from the correlation between the acoustic parameters and the children's responses to the cognitive load assessment questionnaire are presented to confirm the validity of the hypotheses.

The sound of silence: children’s own perspectives on their hearing and listening in classrooms with different acoustic conditions

In this study, we investigated primary school children’s perspectives on their hearing and listening in classrooms with different acoustic quality levels. The sample included 213 children. The children completed a self-report questionnaire rating how well they could hear and listen in various situations in classrooms with two different acoustic conditions: Poor acoustic quality (long reverberation time [Long RT]) versus Adequate acoustic quality (short reverberation time [Short RT]) equipped with a sound-absorbing system. The results showed that auditory perception in the two conditions depends on the child’s age, with only fourth- and fifth-grade children reporting benefits from classroom acoustic correction. Our study provides preliminary results on children’s perspectives regarding their hearing and listening experiences during school learning, drawing out the implications for the design and implementation of school metacognitive interventions aimed at improving children’s and teachers’ awareness of motivational-affective, regulative, and environmental aspects favoring listening at school.

Time-specific Components of Pupil Responses Reveal Alternations in Effort Allocation Caused by Memory Task Demands During Speech Identification in Noise.

Daily communication may be effortful due to poor acoustic quality. In addition, memory demands can induce effort, especially for long or complex sentences. In the current study, we tested the impact of memory task demands and speech-to-noise ratio on the time-specific components of effort allocation during speech identification in noise. Thirty normally hearing adults (15 females, mean age 42.2 years) participated. In an established auditory memory test, listeners had to listen to a list of seven sentences in noise, and repeat the sentence-final word after presentation, and, if instructed, recall the repeated words. We tested the effects of speech-to-noise ratio (SNR; -4 dB, +1 dB) and recall (Recall; Yes, No), on the time-specific components of pupil responses, trial baseline pupil size, and their dynamics (change) along the list. We found three components in the pupil responses (early, middle, and late). While the additional memory task (recall versus no recall) lowered all components' values, SNR (-4 dB versus +1 dB SNR) increased the middle and late component values. Increasing memory demands (Recall) progressively increased trial baseline and steepened decrease of the late component's values. Trial baseline increased most steeply in the condition of +1 dB SNR with recall. The findings suggest that adding a recall to the auditory task alters effort allocation for listening. Listeners are dynamically re-allocating effort from listening to memorizing under changing memory and acoustic demands. The pupil baseline and the time-specific components of pupil responses provide a comprehensive picture of the interplay of SNR and recall on effort.

The effect of room acoustic quality levels on work performance and perceptions in open-plan offices: A laboratory study

A laboratory experiment was performed to explore the effects of acoustic quality levels on work performance and perceptions in open-plan offices. The accuracy rate of the serial recall task and the reported perceptions of the 41 participants were tested at two receiving positions in four office scenarios. According to the revised international standard for measuring room acoustic parameters in open-plan offices, ISO 3382–3:2022, the room acoustic qualities of the four office scenarios were classified into four levels (good, high-medium, low-medium, and poor). The results confirm the validity of the acoustic classification criteria in ISO 3382–3:2022 and highlight that people working in offices with good acoustic quality have significantly higher work performance and acoustic satisfaction than those working in offices with poor acoustic quality. Moreover, comparisons of objective and subjective results between the two receiving positions imply that maintaining a greater distance from people speaking improves work performance and acoustic satisfaction in offices with poor acoustic quality. However, this improvement is insignificant when working in offices with good acoustic quality.

Primary school children’s verbal working memory performances in classrooms with different acoustic conditions

Verbal working memory plays a crucial role in supporting the learning process over the school years. In this study, we investigated the role of the acoustic conditions of school classrooms, specifically reverberation time and babble noise, on second-graders’ verbal working memory. A sample of twenty-five second-graders was administered a validated verbal working memory task in two different acoustic conditions, with a time frame of 1 month: Poor acoustic quality (long reverberation time [Long RT] and babble) versus Adequate acoustic quality (short reverberation time [Short RT] and babble). Results showed that the same children were able to remember fewer words and less accurately on the task in a classroom with longer reverberation time and babble compared to one with shorter reverberation time and babble. Moreover, children omitted more words in the recall task in the Poor acoustic quality condition than in the Adequate acoustic quality condition. The results suggested that primary school children’s verbal working memory processing is sensitive to variations in the classroom acoustic conditions. These findings offer a research contribution about the importance of adopting a contextual view on cognitive development and insights for the implementation of school interventions in terms of metacognitive work on learning to listen and classroom design. • Primary school children’s verbal working memory processing is sensitive to variations in the classroom acoustic conditions. • Results provide support of adopting contextual view on cognitive functioning and development.

Auditory and non-auditory effects, monitoring and mapping of occupational exposure to noise

Abstract Noise, defined as unwanted or misplaced sound, produces negative impacts on people’s health and well-being and is a growing concern of health authorities, administrators, educators. Some reviews of the legislative and regulatory scenarios, show a clear lack of consideration of the non-auditory effects produced by exposure to noise and poor acoustic quality in the workplace, this paper refers to experiences and methods aimed at understanding the different aspects of risk. Non-auditory aspects are added to the auditory ones, considered at the moment as the only area of noise risk assessment. The acute extra-auditory effects from exposure to noise are also studied. Among the risk-enhancing factors we consider the negative synergy between noise and air pollution. Analysis of industrial noise at operator’s positions of different industrial sites was carried out. The results of measurements are allowing determine positions with significant excesses of the sanitary standards of noise levels and valid sanitary norms. Especially significant noise values were observed in low frequency range. Maps of noise levels at working places of different industrial sites were developed.

Preliminary Study of Acoustical Treatment in a Scaled Model Mosque

This paper presents the preliminary study of acoustical treatment in a scaled model of a mosque. The scaled model was constructed with similar use of reinforced concrete wall and dome without acoustical treatment as in the real mosque. This has caused poor acoustic quality especially with high reverberation times (RT). Two different acoustical treatments were applied on the scaled model, i.e. using kenaf fibres and micro perforated panel (MPP) to investigate their effects on the acoustics of the scaled mosque. Experimental measurement was conducted to measure the RT before and after the treatment. It was found that introducing the kenaf fibres and the MPP absorbers had successfully reduced the reverberation time mostly at frequencies above 1 kHz.

Evolution of Models of Working Memory and Cognitive Resources.

The goal of this article is to trace the evolution of models of working memory and cognitive resources from the early 20th century to today. Linear flow models of information processing common in the 1960s and 1970s centered on the transfer of verbal information from a limited-capacity short-term memory store to long-term memory through rehearsal. Current conceptions see working memory as a dynamic system that includes both maintaining and manipulating information through a series of interactive components that include executive control and attentional resources. These models also reflect the evolution from an almost exclusive concentration on working memory for verbal materials to inclusion of a visual working memory component. Although differing in postulated mechanisms and emphasis, these evolving viewpoints all share the recognition that human information processing is a limited-capacity system with limits on the amount of information that can be attended to, remain activated in memory, and utilized at one time. These limitations take on special importance in spoken language comprehension, especially when the stimuli have complex linguistic structures or listening effort is increased by poor acoustic quality or reduced hearing acuity.

Proposals and Analysis of the Effects of Acoustic Corrections in a Modern Church

It is rather common experience to observe that many contemporary churches, in contrast with the effort to achieve refined architectonic shapes and finishes, exhibit poor acoustic quality, such as high reverberation times and low speech intelligibility. The causes of such deficiencies are ordinarily generated by the smooth and hard surfaces of walls, floor and ceiling that focus most of sound energy in late reflections, diminishing the effectiveness of direct and early reflected sound. Recently, the authors have been involved for analyzing the acoustic behavior of a modern church situated in Ragusa, (Italy), with the aim to individuate suitable interventions for improving the acoustic quality of that church. Preliminarily, a measurement survey was conducted to evaluate the main acoustic indices proposed by ISO 3382 (T30, STI, EDT, C80, D50) and portray the current acoustic climate. After that, the Authors developed a simulation on a 3D model of the church, in order to calibrate the model comparing measured and simulated acoustic parameters. The previously described activities are necessary for testing the reliability and accuracy of the prediction of the acoustic simulations. The subsequent step of the work consists in the choice of suitable interventions for the acoustic corrections; three different typologies of materials were evaluated. Globally, the acoustic corrections allow to obtain noteworthy improvements of the acoustic quality of the church, e.g. the T30 decrease from 7.3 to 2.5 s and the STI increase from 33% to 40%, at 1000 Hz. Further, the influence of the variation of the audience presence was analyzed, finding out a strict correlation between occupancy percentage and the law of variation of T30. Finally, after the realizations of one of the suggested interventions of acoustic corrections, the Authors conducted a second survey to evaluate the effects of the refurbishment interventions on the acoustic climate. Since the obtained results do not match very well with the design previsions, some hypotheses that can justify such discrepancy are illustrated.

Acoustic and Luminous Performance Evaluations in Classrooms in Curitiba, Brazil

This study deals with a standardized project in public schools in the Brazilian State of Paraná and analyzes acoustic and luminous qualities in classrooms. The acoustic analysis, conducted by measurements of background noise, reverberation time, and sound insulation, reveals the poor acoustic quality of the classrooms. Acoustic simulation results suggest the need for perforated plywood underneath the ceiling to reduce reverberation time and increase the overall acoustic comfort of the classrooms. The luminous performance analysis is based on computational simulations with daylighting programs for different combinations of days, schedules, and solar orientation of the buildings. Results show daylighting levels for various positions of the building. This allows the designer to choose the best way of siting the building with respect to aspects of the locality and the resulting quality of the indoor space. Finally, shading elements are designed for each orientation in order to improve daylighting levels and the building's overall thermal performance.

Perception of teachers and pupils to the acoustics of classrooms

The present survey has evaluated the acoustic characteristics of classrooms built as modular classrooms. The study has focused on the background noise, reverberation time, noise insulation and interviews with teachers and pupils. The acoustic comfort of classrooms in a Brazilian public school has been evaluated through interviews with 62 teachers and 464 pupils. Acoustic measurements have revealed the poor acoustic quality of the classrooms. The walls between the classrooms and the corridor have permanent ventilation openings on glassy bricks. The measured weighted apparent sound reduction index (ISO 140‐4; ISO 717‐1) for the wall, with a door and glassy brick, was R'w = 17 dB. The low value of the weighted apparent sound reduction index R'w= 17 dB contributes significantly to the noise transmission from one room to the other, contributing to the elevated levels of background noise inside the classrooms. Interviews with teachers and pupils have shown that the main noise sources noted in the classrooms originate inside the school: voices of students and of the teacher of the neighboring classroom.

Objective and subjective evaluation of the acoustic comfort in classrooms

The acoustic comfort of classrooms in a Brazilian public school has been evaluated through interviews with 62 teachers and 464 pupils, measurements of background noise, reverberation time, and sound insulation. Acoustic measurements have revealed the poor acoustic quality of the classrooms. Results have shown that teachers and pupils consider the noise generated and the voice of the teacher in neighboring classrooms as the main sources of annoyance inside the classroom. Acoustic simulations resulted in the suggestion of placement of perforated plywood on the ceiling, for reduction in reverberation time and increase in the acoustic comfort of the classrooms.

Objective and subjective evaluation of the acoustic comfort in public classrooms

The acoustic comfort of classrooms in a Brazilian public school has been evaluated through interviews with 62 teachers and 464 pupils and measurements of background noise, reverberation time, and sound insulation. Acoustic measurements have revealed the poor acoustic quality of the classrooms. Results have shown that teachers and pupils consider the noise generated and the voice of the teacher in neighboring classrooms as the main sources of annoyance inside the classroom. Acoustic simulations resulted in the suggestion of placement of perforated plywood on the ceiling, for reduction in reverberation time and increase in the acoustic comfort of the classrooms. [Work supported by DAAD, CNPq and FINEP.]

Acoustic refurbishment of a large-volume gymnasium by means of a lightweight suspended absorbing ceiling

A suspended-grid absorbing ceiling was installed in a gymnasium that was originally of poor acoustic quality. The ceiling resulted in reverberation times suitable for speech but was light enough to be borne by the structure. The natural lighting through the roof lights remained sufficient to illuminate the gymnasium in daytime, and the finish was light, reflective, and elegant.